Programmer PIC16F84/A

Buy Sex Toys Online

2011-12-05T21:48:00.002Z

Yesterday I met with my old friend at a mall in our city. We are involved because it had long intimate conversations we have not seen since graduating from college. Indeed, he looks a little different when compared to college.

My friend also has a very good job in government and he really enjoys the job because it was his goal since early childhood.

But he looks a little gloomy at the time of the meeting. As a friend of course I immediately asked him why he looked glum. Then he told me that his marriage to his wife a little less happy. This is because he was experiencing a few problems with sexual. That he could not last long so can not make happy to his wife.

Therefore, he asked me where can safely buy sex toys are over the internet. Of course I immediately advised him to visit http://www.hotgvibe.com/ because there are a variety of sex toys as desired.

A variety of sex toys available such as cock ring,dildos, pocket pussy, vibrators, sexual enhancers, and others. My friend would be satisfied if shopping on the website.

After meeting a few months later he called me saying that he had been spending on the website that I recommend it, and he was very satisfied with the services on the website. He is very grateful to me for showing the website which could ultimately save the marriage.

1Hz - 2MHz XR2206 Function Generator Kit

2011-11-20T13:45:00.004Z

Premium quality XR2206 Function Generator kit capable of producing high quality sine, square and triangle waveforms of high-stability and accuracy. The output waveforms can be both amplitude and frequency modulated. Coarse frequency adjustment is accomplished using 4-DIP switch for the following four frequency ranges; (1) 1Hz-100Hz, (2) 100Hz-20KHz, (3) 20KHz-1MHz, (4) 150KHz-2MHz. Frequency output can be fine tuned using P1 and P2 potentiometers. The kit includes output that can be connected to 60MHz Counter kit for displaying output frequency on LCD display with green backlight. 1Hz - 2MHz XR2206 Function Generator kit includes premium quality components, including Audio Grade Gold Capacitors, Gold Plated RCA Connector, WIMA Capacitors, 1% Metal Film Resistors, two external switches and premium quality double-sided PCB with red solder mask and plated through holes.

XR2206 Function Generator Schematic

Sine Wave:
Amplitude: 0 - 3V at 9V DC input
Distortion: Less than 1% (at 1kHz)
Flatness: +0.05dB 1Hz - 100kHz

Square Wave:
Amplitude: 8V (no load) at 9V DC input
Rise Time: Less than 50ns (at 1kHz)
Fall Time: Less than 30ns (at 1kHz)
Symmetry: Less than 5% (at 1kHz)

Triangle Wave:
Amplitude: 0 - 3V at 9V DC input
Linearity: Less than 1% (up to 100kHz)

Specifications:
Voltage Supply: 9-18V DC Input
Waveforms: Square, Sine & Triangle
Impedance: 600Ω + 10%
Frequency: 1Hz - 2MHz in 4 steps ranges with fine adjustment
PCB Dimensions: 38mm x 69mm / 1.5" x 2.7"

Component List:
1x XR2206
1x Premium Quality PCB with Red Solder Mask
1x Gold Plated RCA Connector
1x Gold Plated 4-DIP Switch
1x Sine / Square Switch
1x Sine / Triangle Switch
2x 100K Potentiometer
1x 10K Potentiometer
1x 100uF / 50V Nichicon Gold Audio Grade Capacitor
2x 10uF / 35V Nichicon Gold Audio Grade Capacitor
1x 100nF WIMA Capacitor
1x 1nF WIMA Capacitor
1x 150pF Capacitor
3x 6.8K 1% Metal Film Resistor
2x 1K 1% Metal Film Resistor
1x 3-PIN Gold Plated Male Header
2x 2-PIN Gold Plated Male Header
1x Manual with Schematic

Pornxchange.com

2011-10-16T12:42:00.001+01:00

Yesterday I met with my old friend. We chatted with a very familiar from the start of work until the personal stuff. Among them we discuss our favorite past time is still young, that visiting porn sites.

Yes we are very familiar and friendly arguably have a similar passion. We really liked the things that are porno.Walaupun we never break the rules and norms of decency.

We each have our favorite porn sites on their own. We even have our favorite porn stars on their own. That's when I met my friend introduced to me about pornxchange.

Pornxchange site contains about site review porn sites and porn stars star review as well. We will be made easier by visiting pornechange once.

Out of curiosity, then coming home from a meeting with my friend, I immediately opened the website pornxchange.com as suggested by my friend. And it was the site does not disappoint!

Bang You Later

2011-08-12T14:11:00.001+01:00

Many of my friends who visit adult websites. They mostly liked the site that gives a free adult video like youporn.com, pornhub.com, redtube.com, xvideos.com, etc.

I really like best friends visit the site because it gives the facility of free download adult videos. But yesterday he had called me and asked if I know another site that gives a nicer facility to download adult videos.

Of course I later gave the name of an adult site that is Bang You Later that address at http://www.bangyoulater.com/videos/. This site is quite good porn sites. Of course you must be aged over 18 years of age to visit this site.

Finally my friend trying to check a site that I give you this and he commented that the site is relatively new compared to other similar sites but has a quality not inferior to the other sites.

Tummy Tuck on Rodeo Drive

2011-06-30T21:38:00.003+01:00

My sister called me one day, he asked me to deliver him to perform surgery because of excess skin around stomach .The excess skin on his stomach occurs due to pregnancy.

Apparently he wanted to do abdominoplasty. Abdominoplasty is a process is a major surgical procedure to remove excess skin and fat from the middle and lower abdomen and to tighten the muscles of the abdominal wall. This process is often referred to as a "tummy tuck".

I immediately urged my brother to do the initial preparation operations such as stopping smoking, or stop taking medications or vitamins. And will consult in advance before the actual surgery.

For surgery process, I will entrust to the Plastic Surgeon in Los Angeles - Dr. Lloyd Krieger that is located at Rodeo Drive Plastic Surgery
421 North Rodeo Drive
second Floor
Beverly Hills, CA 90210

Here can perform various types of surgery such as tummy tuck, liposuction and breast augmentation.

My sister impatient for immediate surgery tummy tuck in order to get a good belly shape as before the pregnancy.

Lu Ross Academy

2011-06-23T14:04:00.002+01:00

My female friend asked me one day that she wanted to learn about beauty. We live in a city in the United States. Then I asked what areas of the field he wanted a commitment.

Turns out he wanted to learn all things related to beauty, cosmetology, and about the makeup artist., Hair styling, hair coloring, hair cutting and others.

Hearing this I immediately tried to find a place to learn is right for my female friends are. Fortunately, I later found out Lu Ross Academy, which is the California Cosmetology School.

Lu Ross On Cosmetology School California there are many subjects such as hairdressing, haircut, makeup artist, skin care, facials, microdermabrasion up.

Also available is a program that includes makeup artist makeup straight, TV makeup and makeup special effects. Get a very clear description of the above, I was immediately interested in female friends to join Lu Ross Academy because here is the most comprehensive CaliforniaCosmetology School in California.

One day, he called me and said that he had learned at Lu Ross Academy. I could only smile happily.

Freedom Treatment Center

2011-05-29T14:49:00.003+01:00

I do not think that I got a call from my brother stating that her son had been addicted to drugs. Therefore , my brother was very afraid of the future of the son.

Hearing this I immediately suggested to my brother to immediately take his son to drug addiction rehab.

Finally, I soon find a place to rehabilitate drug addiction through Google by using keywords of Drug Addiction Treatment or just Drug Treatment . Finally I found a very representative place to help victims of drug addiction. Website address is http://www.freedomdrugrehab.com.

Very nice place with bedsroom very clean and comfortable. There is also a special room for relaxation. If your brother is also mnegalami something similar, then immediately contact the Freedom Center with a tool free 1 (877) 394-1828.

Liposuction on Rodeo Drive

2011-04-08T12:45:00.002+01:00

My brothers who are overweight asked me where to perform liposuction. We happened to live in Los Angeles, USA. My brother felt that too much fat in their bodies that interfere with the operation or activities of daily activities.

Therefore, I urgently seeking information about liposuction here in Los Angeles. Through the information of a friend, he suggested me to go to Rodeo Drive Plastic Surgery. All we knew there was a famous physician of Dr. Lloyd Krieger work on the famous Los Angeles Plastic Surgery.

We immediately contacted the Rodeo Drive Plastic Surgery to make an appointment to meet. It turns out that the Rodeo Drive Plastic surgery is the best Los Angeles plastic surgery.

Rodeo Drive Plastic Surgery was also Los Angeles breast augmentation and rhinoplasty also very completed throughout Los Angeles. Soon my brother who had immediately wanted to do liposuction immediately contacted the Rodeo Drive Plastic Surgery to immediately meet with Dr. Lloyd Krieger.

Build Solar Engine

2011-03-17T13:58:00.009Z

The solar engine is commonly used as an onboard power plant for BEAM-type robots. Sometime called living robots. The inspiration for this solar engine originated from Mr. Mark W.Tilden who originally designed a solar engine.

Another innovator was Dave Hrynkiw from Canada. He modified the solar engine design to power a solar ball robot. Below figure is schematic for the solar engine. This design are take from book with title Robot, Android, and Animatron by Jhon Iovine.

Figure Schematic Solar Engine

Here is how it works. The solar cell charges the main 4700uF Capacitor as a power banks. As the capacitor charges the voltage level of the circuit increase.The UJT ( Uni Junction Transistor ) begin oscillating and sending a trigger pulse to the SCR ( Silicon Controlled Rectifier ). When the circuit voltage has risen to about 3 Volt from the main capacitor, the trigger pulse is sufficient to turn on the SCR. When SCR turn on , all the stored power in the main capacitor is dumped trough the high efficiency motor ( HE-motor ).

The motor spins momentarily as the capacitor discharges and then stops. The cycle repeat.

Education And Careers

2011-01-30T09:55:00.002Z

My brother, the son of my uncle was looking for a place for adults education . He asked for my help in finding a place to learn it. Finally I asked my friend who once studied online.

My friend gave the website address to find a place of study for adults is http://www.classesandcareers.net/. Here we can easily find a place to go to college. In addition, this website also provides information about careers.

Finally, together with my brother I was immediately access the website. It turns out there on the web is the "Quick Degree Finder" which is very easy looking for a place in college. Soon we use search facility where the course.

After a while, my brother finally found the place of study as coveted. I am very grateful to www.classandcareers.net who have helped my brother find a college that was looking for.

SCANNING KEYPAD

2011-01-01T09:32:00.003Z

Keypad are available wired in various ways. If the switches are arranged in a matrix, they can be scanned by a microcontroller to see if one of the switches is closed ( i.e a key is pressed ). For 5 swiched/keys or less, it is best to use one port liner per switch/key.For 6 keys or more, a matrix arrangement is most efficient (minimize number of port lines ).

The keypad shown below has 12 switches arranged in a 4 row by 3 column matrix. Pressing a key closes a switch which electrically connects one row to one column.

Each keypad switch in the matrix is connected to the microcontroller as shown :

At the time the input port line is read, its logic level depends, first, on whether the switch is open or closed. If the switch is closed, the logic level at the input port line will be the same as the output port line logic level.

Find Online College and Universities

2010-12-30T12:18:00.000Z

Yesterday, the son of my brother asked me for help finding an online school. He is looking for an online school because no other work so as not to busy school / college are common.

Therefore, I just search using google search engine and then I found a website online school about a very bonafide namely www.elearners.com. Through www.elearners.com I can find online schools by just 4 easy steps.

We can find online schools directly from the search box on the website then click go . Or we can also choose subject we want, it could be a degree level or directly select any college or university that has been available. It's really easy and does not require a long time.

After a while weighing, younger brother finally I choose one of the online school. I am sure with so many choices on this online school will be more easier for my brother to find the best school for him.eLearners.com100 thanks very much for your support.

Find Online College

2010-12-30T11:55:00.003Z

This year my sister had graduated from high school and will soon continue higher education. But because he must help parents to work, then he will find an online college.

After much searching on the internet, we finally found a place online that is very complete of the lecture. From the start of Art and Design, Criminal Justice through Technology. Online College is what I mean is Earnmydegree.com.

Online College is already working with many of leading schools and they have training carrier opportunities. Among those schools, including: Abilene Christian University, Alliant International University, Allied schools and many others. Everything can be selected directly via their official website.

Therefore, a very complete facilities from earnmydegree.com, my sister finally decided to study online through earnmydegree.com. My family and felt grateful to have found a place online college for my sister.

Easy Online Payday Loan

2010-10-26T14:21:00.003+01:00

One time I had experienced an emergency where I need to provide money for parents who live in villages. It was pay-day has not arrived and still long. However, due to the need for these funds is very important, so I'm looking for ways to get funds.

Some of my friends call to borrow money from him. But many of my friends also do not have excess money. This is because pay-day me and my friends almost simultaneously.

Soon came an short message service from my friend who told me to borrow funds from easyonlinepaydayloan.com. Soon I opened the website and very interested in the facilities it provides.

Finally, I fill out the form online, and upon approval, funds are given on the spot directly into my bank account. Very quick and simple! This is faxless payday loan

When payday comes, I do not forget I pay my loan in easyonlinepaydayloan.com

Car Insurance Rates

2010-10-26T14:07:00.002+01:00

One time my boss told me to find companies for car insurance. Of course I was somewhat surprised because I do not know many car insurance companies.

Finally I try to ask our friends, about what car insurance company best car for my boss. Friends who suggested that many companies take the premiums expensive car insurance, car insurance for more leverage.

To increase my knowledge of car insurance will, at last I opened open the website and met with carinsurancerates.com. I saw that the website is very useful for people like me who are looking for car insurance companies.

Many are companies that are discussed such as Mercury, Metlife or Liberty Mutual. But I read the first reading the entire contents of carinsuracerates.com to choose a car insurance company in accordance with the budget my boss.

Soon I had to choose the best car insurance company for my boss. Thank-you carinsurancerates.com.

Cash Advance Payday Loan

2010-10-26T13:50:00.002+01:00

As a family we have to pay extra expenditure to fix damage to the car, we had difficulty because it does not have the cash. At that instant payday is still too long.

But we remember will notice a friend, that we can borrow the money before payday arrives us. This is because we wanted to borrow money is not too big.

Finally we contact Personalcashadvance.com to get a Payday loan. Apparently the process is very simple and requires only a very short time.

What I do is fill out a clear form that has been provided, after which watu within 24 hours I had to get the loan! Besides, Financial tools are also available which is very helpful for managing finances.

With the help of my family personalcashadvance finally get the funds as I need before the payday arrives. We really helped with the service provided by personalcash advance.com

Urgent Cash Loan

2010-10-26T13:39:00.004+01:00

When our family was in a state of financial difficulty because there are a few of our family business that loses money. At that time we so need financial assistance in order to survive in order not continue losing money.

We immediately went to several local banks to ask for a loan. But what we get is a convoluted process and requires a very long time. And then we really need help with funding!

Finally on the advice of friends, he told me to immediately open urgentcashloan.com. Without thinking I immediately run the suggestion of my friend. And it's true! UrgentCashLoan.com can provide loans quickly with just a few easy steps of filling a simple form, immediately send the form and receive various types of credit.

Finally our family get fast cash advance and this help our family bussiness to improved.

Life Insurance

2010-10-26T13:07:00.003+01:00

At that time my mother asked me to find information about life insurance. Quickly, I simply look straight from the internet and my attention turned to a website that is very interesting to me.

This website is lifeinsurancerates.com. I immediately read it to find a variety of life insurance offered. This website has really helped me to find a suitable provider of life insurance with my mother's economic circumstances.

By using lifeinsurancerates.com I can compare different types of life insurance offered by many companies such as AIG Insurance, Metlife, Mutual, Prudential etc.

Lifeinsurancertes.com provide information for the whole life insurance in the world that can be easily accessible for all of us.

Finally, after study of a wide selection of life insurance, then my mother has chosen one of life innsurance trusted. Thanks lifeinsurancerates.com for your effort to my family.

AIR INTAKE

2010-07-21T14:45:00.003+01:00

Yesterday I was browsing the intenet to find the product of the cold air intake. My friend has asked me to find the product of cold air intake which good and cheap that according to his car.

A cold air intake is a device to bring air into the low-temperature combustion engines in cars to improve energy efficient car. All cold air intake work with the principles by raising the oxygen content which is available for combustion using gasoline (fuel). Because the cold air that usually contain a lot of content (mass) per volume.

Finally, my eye was attracted by a very interesting website that is AIR INTAKE SYSTEM . On this website available a variety of cold air intake that is suitable for most production cars past and present include: BMW air intake, Audi Air Intake , Bentley Air Intake, Daewoo air intake etc.

Therefore, I simply chose cold air intake according to my friend's car and immediately told my friends about this website. It is a bit hard to choose it because there a lot of models.

Finally my friend was satisfied with the product which is available on this AIR INTAKE SYSTEM and soon will make the buying process as soon as possible. To ensure that the goods are ordered there so my friend called up immediately via toll-free at 800-505-3274. Fortunately they were open 7 days per week and is available live chat facility.

Moreover in here also provides a variety of other auto parts that you need such dash kit, custom grille, floor mats, chrome accessories, rear spoilers etc. related product to the needs of your car. Find stuff feels very interesting in at this website. I guarantee that you also will love to shop here.

2010-07-18T04:21:00.005+01:00

Now I have made a new website to download Ebook microcontroller, robotics, electronics, Electronics/Robotics Magazine, Internet Marketing etc.

If you have ebook with the same theme and want to share with your friend, please contact me i will upload your ebook so others can download your ebook.

I will update this website until the number of ebook will more and more each day and you can benefit from it.

Ok, don't waste a time just go to Download-ebook.webs.com.

Get PAid for Reading and $haring articles

2010-07-10T13:26:00.001+01:00

Earn $10 RIGHT NOW
While in pre-launch until August 1st, 2010 as soon as you register for IMCREW you get a $10.00 Bonus credited to your account!!!

Earn $2 for every referral
Until the 1st of August, we are in the pre-launch stage to gain more exposure and new members. During this time, if you register and refer your friends, you'll earn $2 for EVERY active member you refer, plus, you'll earn 20% of whatever they earn in the future!!!

IMCREW is brand new, FREE membership website for those who want to start making money online by reading and promoting articles about various methods to make money online. Until the 1st of August, we will be in the pre-launch stage (that means now you you are able to build your downline as you will earn 20% of your referral's earnings for the lifetime of their active account and earn a $2 BONUS for every member you refer to IMCREW while pre-launch) You don't need any experience and you won't need to pay for anything and you will be able to earn up to $1275/month simply by reading and promoting IMCREW's articles.

Click Here to join.

IF YOU WANT TO TAKE A LOAN

2010-06-08T13:15:00.003+01:00

During browsing on internet last night, I stopped on a website that can give a loan for business or for personal. That site is EZUnsecured.com from EZUnsecured Company that expert in Unsecured Business Financing. Here in EZUnsecured we can get a loan in just a day. Fantastic.

Beside of personal and business loan, EZUnsecured can also help you in Equipment Leasing, Software Leasing, Practice Financing and help you to Expand your business. With long experience since established in 2002. There are no doubt about their service.

To improve your Business Finance don't hesitate to contact EZUnsecured for assistant. This company not only serve Business Finance, but also Small Business Finance . Regarding this site, many people have succeeded during apply to loan to EZUnsecured Company.

So if you need company that can help you for Small Business Financing don't take a long time just visit EZUnsecured.com right now ! Just take a action for your improvement of your Business.

I will also inform to all my colleague about this site that very interesting for huge loan. Even we can see the video of their service by just visiting EZUnsecured.com. Don't think to much time, just visit EZUnsecured.com and get the loan.

Advertisers, You can now buy links on my website directly!

2010-05-28T03:00:00.000+01:00

I have recently joined ask2link.com (http://www.ask2link.com/refer/mohibnumalik) to enable advertisers to buy text links advertisement on my website. ask2link's text links are unique since they could bring targetted traffic and boost your organic search engine rankings. ask2link.com provides secure, easy, and fast checkout flow so you could get your text link ads live within five minutes.Bloggers or Webmasters: If you would like to monetize your blog or website beyond Adsense, you could visit ask2link (http://www.ask2link.com/refer/mohibnumalik) to learn more.Buy text link ads now on this website with ask2link. Start advertising now in this website as part of your online marketing campaign. You could now purchase text link ads on this website by following here: http://www.ask2link.com/buy_ad/137dc3faecac8d91df251274974262Note to advertisers, SEO agencies/SEO specialists, internet marketers, or e-commerce websites: You could visit ask2link - http://www.ask2link.com/refer/mohibnumalik -to buy static text links on hundreds of websites easily as part of your inbound link building and SEO campaign.They accept credit cards and PayPal payments and your text links will be live within five minutes after your order.ask2link's text links are unique because they are rendered as plain static HTML links that could bring you moretraffic and boost your organic search engine ranking for your keywords.-------Thanks,

Zenni Optical

2010-03-25T16:10:00.002Z

When my brother want to buy eye glasses, I recommend him to open website of Zenni Optical. This is because Zenni Optical sell low price of prescription eye glasses starting for just eight bucks.

I have purchased from Zenni Optical and very satisfied with the product. I have more proud after reading Eric's Review about Zenni Optical. Eric explain more about Zenni Optical product and the benefit using their product.

Finally my brother also satisfied using eye glasses from Zenni Optical. Not only the price that very cheap, but also they have many kind of frame that meet with your need.

LIQUID CRYSTAL DISPLAY INTERFACE ( Part 1 )

2009-06-19T01:04:00.009+01:00

Liquid Crystal Display ( LCD ) are now available which are inexpensive, display alphanumeric character, require only 14 wires for connection and are simple to use. They come 16 to as many as 40 characters wire and 1,2, or 4 lines high.

1 x 16 LCD
The 1 line by 16 character display ( produced by some manufactures ) is controlled by a Hitachi HD44780 LCD controller chip which is surface mounted on the back side of the display module’s printed circuit board. The HD44780 display controller is commonly used in a variety of liquid crystal display made by manufacturers such as Hitachi, Optrex, Amperex, Densitron and Epson. The following description will apply in a general way to similar displays made by these manufacturers.

PIN & FUNCTION

1 GND Connect to Ground
2 +5V Connect to Power supply +5V
3 Vref Brightness Control Voltage
4 RS ( Register Select ) control line
5 R / W Read / Write Control – connect to ground for simple app.
6 E Enable control line
7 D0 Data 0 line
8 D1 Data 1 line
9 D2 Data 2 line
10 D3 D ata 3 Line
11 D4 Data 4 line
12 D5 Data 5 line
13 D6 Data 6 line
14 D7 Data 7 line

15 + Back light ( + )
16 - Back light ( - )

The display module has 3 control lines. RS makes the selection of instructions vs data and may be thought of as an address line which select either the control register or the data Register.
The R/W line set up for read vs write. For this application the display will be written to only, so this line brought to ground. E enable the display registers for a write operation when High.

Port Bit(s) Function
B0 – 7 Data
A 2 RS ( Register Select )
A 1 E ( Enable )

Data VS Instruction
There are 2 port and some timing involved in controlling the display. The display control lines are set up before sending either an instruction word or a data word. The RS line is asserted 0 for sending an instruction or 1 for sending data.

Function for sending RS
Instruction 0
Data 1

This must be done in advance of pulsing the enable line high. Also the data or instruction byte must be stable at port B prior to pulsing the enable line High.

Display Control
Instruction words are sent to the display to tell it what mode to operate in.

Operation Instruction word Function
Function Set 0x38 8bit, 5x7
Used at initial only
Display on/off 0x0C Display on,no cursor
0x0F Display on, cursor blink
Clear Display 0x01 Clear Display = Blanks
Entry Mode Set 0x06 Increment Mode

Character Addresses
Each of the 16 display characters has an address. This tells the display controller where to put the next character data byte.

We will need some code to initialize the display to test the demonstation circuit. This will consist of a short main program which delay 5 miliseconds to allow the LCD microcontroller time to get itself organized after power-on reset ( essential ), an initialization routine for sending the LCD its operation mode instruction and a second 5 ms delay .
( Continue next ……see u ….)

Source : Pic’n Up the Pace

Download PDF

PIC TO PIC SERIAL COMMUNICATION

2009-06-18T00:57:00.008+01:00

In an effort to expand our serial communication capabilities, we will get a couple of PIC16F84 to talk to each other. Actually we’ll do part of the job by getting one PIC16F84 to talk while the other listens.

We’ll see if the listener understood what the talker said. We will set this up so you can continue on your own by sending more than one word and by interchanging the talk/listen roles ( two-way communication ).

Both PIC16F84 with 4 MHz clock oscillators. For the transmitting chip, port A, bit 1 is used to transmit. The receiver uses port A, bit 0 to receive. We will choose the bit time interval as 256 internal clock ( 1 MHz ) cycle. Both transmitter and receiver will use TMR0 for timing.

When the transmit data ( TD ) line is high, the condition is known as “mark”. When TD is low , the condition is known as “Space”. The terminology comes from the old teletype days.
When one word ( 8 bits ) is sent, the TD line output vs time will look like this :

;=======P2PSEND.ASM=================================4/29/97==
list p=16f84a
__config h'3ff1'
radix hex
;------------------------------------------------------------
; cpu equates (memory map)
tmr0 equ 0x01
status equ 0x03
porta equ 0x05
intcon equ 0x0b
sendreg equ 0x0c
count equ 0x0d
optreg equ 0x81
trisa equ 0x85
;------------------------------------------------------------
; bit equates
c equ 0
rp0 equ 5
;------------------------------------------------------------
org 0x000
;
start bsf status,rp0 ;switch to bank 1
movlw b'00000100' ;port A inputs/outputs
movwf trisa
bcf status,rp0 ;switch back to bank 0
bsf porta,1 ;output mark, bit 1
movlw 0x80 ;number to be sent
movwf sendreg ;store
switch btfsc porta,2 ;start send?
goto switch ;not yet
call ser_out ;to serial out subroutine
circle goto circle ;done
;------------------------------------------------------------
ser_out bcf intcon,5 ;disable tmr0 interrupts
bcf intcon,7 ;disable global interrupts
clrf tmr0 ;clear timer/counter
clrwdt ;clear wdt prep prescaler assign
bsf status,rp0 ;to bank 1
movlw b'11011000' ;set up timer/counter
movwf optreg
bcf status,rp0 ;back to bank 0
movlw 0x08 ;init shift counter
movwf count
bcf porta,1 ;start bit
clrf tmr0 ;start timer/counter
bcf intcon,2 ;clear tmr0 overflow flag
time1 btfss intcon,2 ;timer overflow?
goto time1 ;no
bcf intcon,2 ;yes, clear overflow flag
nxtbit rlf sendreg,f ;rotate msb into carry flag
bcf porta,1 ;clear port A, bit 1
btfsc status,c ;test carry flag
bsf porta,1 ;bit is set
time2 btfss intcon,2 ;timer overflow?
goto time2 ;no
bcf intcon,2 ;clear overflow flag
decfsz count,f ;shifted 8?
goto nxtbit ;no
bsf porta,1 ;yes, output mark
time3 btfss intcon,2 ;timer overflow?
goto time3 ;no
return ;done
;------------------------------------------------------------
end
;------------------------------------------------------------
;at device program time, select:
; code protection off
; watchdog timer disabled (default is enabled)
; standard crystal XT (using 4 MHz osc for test)
; power-up timer on
;============================================================

source : pic'n up the pace

Download PDF

Serial EEPROM

2009-06-14T09:09:00.007+01:00

Serial EEPROMs come in three main flavors and variety of sizes. The 93XXX devices are the easiest to interface to microcontroller PIC16F84/A.

The 93C46 is a small non volatile memory peripheral chip. It is organized as 64 registers of 16 bits each. The programming voltage and write timing are developed on-chip. The self timed write cycle takes about 10 miliseconds.

All communication with the 93C64 begins with sending 9 instruction bits. The first bit ( MSB ) is a logic “1” start bit. The remaining 8 bits may be an op code or an op code and address combination. If the operation is a write operation, 16 data bits follow the instruction bits, MSB first.

This chip have control line as follow :

Serial data In
Serial Data Out
Clock
Chip Select

Some use rules are :

A register must be erased ( all 1’s ) before it can be written to. The chip has a built in auto erase cycle which takes place when a write is called for.
The chip select pin ( CS ) must be brought low for a minimum of 1 microsecond between consecutive instruction cycles to synchronize the internal logic of the device
For read operations, a dummy “0” precedes the 16 data bits. Data is shifted out MSB first.
Completion of an erase cycle or write cycle to an individual memory location takes about 10 milliseconds. The serial data output ( DO ) pin may also be used as a status pin during the self timing phase of these operation to indicate the status of the device.

On completion of erase or write, CS is brought low briefly. After that, DO will be low until the operation is complete. When DO goes high again, the device is no longer busy and is accessible for other operations.

;=======93C46.ASM===================================4/26/97==

list p=16f84a

__config h'3ff1'

radix hex

;------------------------------------------------------------

; cpu equates (memory map)

status equ 0x03

porta equ 0x05

portb equ 0x06

cook equ 0x0c

hibyte equ 0x0d

count equ 0x0e

address equ 0x0f

data_hi equ 0x10

data_lo equ 0x11

temp equ 0x12

trisa equ 0x85

trisb equ 0x86

;------------------------------------------------------------

; bit equates

rp0 equ 5

;------------------------------------------------------------

org 0x000

;

start bsf status,rp0 ;switch to bank 1

movlw b'00000001' ;bit 0 = input

movwf trisa

movlw b'00000000' ;outputs

movwf trisb

bcf status,rp0 ;switch back to bank 0

bcf porta,1 ;initialize

bcf porta,2 ;initialize

bcf porta,3 ;initialize

movlw 0x00 ;00000000

movwf portb ;LEDs off

movlw 0x00 ;define test address

movwf address

movlw 0x80 ;define test hi byte

movwf data_hi

movlw 0x0f ;define test lo byte

movwf data_lo

call write ;write subroutine

call read ;read subroutine

movf cook,w ;get lo byte

movwf portb ;display via LEDs

circle goto circle ;done

;------------------------------------------------------------

ewen movlw 0x30 ;ewen op code

movwf cook ;to cook

bsf porta,1 ;send start bit

bsf porta,2 ;shift

bcf porta,2

call sendbits ;send ewen op code

return

;------------------------------------------------------------

ewds movlw 0x00 ;ewds op code

movwf cook ;to cook

bsf porta,1 ;send start bit

bsf porta,2 ;shift

bcf porta,2

call sendbits ;send ewds op code

return

;------------------------------------------------------------

write bsf porta,3 ;cs high

call ewen ;erase/write enable

bcf porta,3 ;cs low

nop ;1 microsecond min

bsf porta,3 ;cs high

movf address,w ;get address

movwf cook ;store in cook

bcf cook,7 ;op code

bsf cook,6 ;ms 2 bits

bsf porta,1 ;send start bit

bsf porta,2 ;shift

bcf porta,2

call sendbits ;send address

movf data_hi,w ;get data hi

movwf cook

call sendbits ;send data hi

movf data_lo,w ;get data lo

movwf cook

call sendbits ;send data lo

bcf porta,3 ;cs low

nop ;1 microsecond min

bsf porta,3 ;cs high

ecycle2 btfss porta,0 ;erase cycle complete?

goto ecycle2 ;not yet

bcf porta,3 ;cs low

nop ;1 microsecond min

call ewds ;yes, erase/write disable

bcf porta,3 ;cs low

nop ;1 microsecond min

return

;------------------------------------------------------------

read bsf porta,3 ;cs high

movf address,w ;get address

movwf cook

bsf cook,7 ;op code

bcf cook,6 ;ms 2 bits

bsf porta,1 ;send start bit

bsf porta,2 ;shift

bcf porta,2

call sendbits ;send address

call getprom ;shift hi 8 bits out of eeprom

movf cook,w ;hi byte result in hibyte

movwf hibyte

call getprom ;shift lo 8 bits out of eeprom

bcf porta,3 ;cs low

nop ;1microsecond min

return ;exit sub with lo byte in cook

;------------------------------------------------------------

sendbits movlw 0x08 ;count=8

movwf count

sbit call sendbit ;send 1 bit

decfsz count,f ;done?

goto sftcook ;no

return ;yes

sftcook rlf cook,f ;shift cook left

goto sbit ;again

;------------------------------------------------------------

sendbit bcf porta,1 ;default

btfsc cook,7 ;test cook bit 7

bsf porta,1 ;bit is set

shift1 bsf porta,2 ;shift

bcf porta,2

return

;------------------------------------------------------------

getprom movlw 0x08 ;count=8

movwf count

shift2 bsf porta,2 ;shift

bcf porta,2

movf porta,w ;read port A

movwf temp ;store copy

rrf temp,f ;rotate bit into carry flag

rlf cook,f ;rotate carry flag into cook

decfsz count,f ;decrement counter

goto shift2

return ;done

;------------------------------------------------------------

end

;------------------------------------------------------------

;at device program time, select:

; code protection off

; watchdog timer disabled (default is enabled)

; standard crystal XT (using 4 MHz osc for test)

; power-up timer on

;============================================================

;------------------------------------------------------------

erase bsf porta,3 ;cs high

call ewen ;erase/write enable

bcf porta,3 ;cs low

nop ;1 microsecond min

bsf porta,3 ;cs high

movf address,w ;get address

movwf cook ;store in cook

bsf cook,7 ;op code

bsf cook,6 ;ms 2 bits

bsf porta,1 ;send start bit

bsf porta,2 ;shift

bcf porta,2

call sendbits ;send address

bcf porta,3 ;cs low

nop ;1 microsecond min

bsf porta,3 ;cs high

ecycle1 btfss porta,0 ;erase cycle complete?

goto ecycle1 ;not yet

bcf porta,3 ;cs low

nop ;1microsecond min

call ewds ;yes, erase/write disable

bcf porta,3 ;cs low

nop ;1microsecond min

return; NOP are use to ensure that the 93C64 chip’s timing requirement are met.

Source : pic’n up the pace

Download PDF

PARALEL IN , SERIAL OUT SHIFT REGISTER 74HC165

2009-06-13T00:58:00.006+01:00

Bringing 8 bits of data into a PIC16F84 serially is done in a similar way. For that purpose we can use 74HC165 parallel in serial out shift register.

This digital IC has 3 control lines as follow :

1. Serial Output
2. Load ( load 8 bits into shift register )
3. Clock ( shift data MS bit first )

The 8 bits of data presented to the shift register are latched in using the LOAD control line. The 8 data bits are shifted out most significant bit first.

One port pin of PIC16F84/A is used for serial in. It is convenient to use bit 0 for serial input. The program looks at the port as a whole, rotate bit “0” into the carry flag, and rotate the content of the carry flag into the least significant bit ( LSB ) of the file register assigned to receive the incoming data.

This process is carried out for each of the 8 bits. Notice that the first bit is available at the serial output line immediately after the data is latched. Shifting 7 times ( not 8 times ) is required to access the remaining bits.

;=======74HC165.ASM=================================4/25/97==
list p=16f84a
__config h'3ff1'
radix hex
;------------------------------------------------------------
; cpu equates (memory map)
porta equ 0x05
portb equ 0x06
status equ 0x03
rcvreg equ 0x0c
count equ 0x0d
temp equ 0x0e
trisa equ 0x85
trisb equ 0x86
;------------------------------------------------------------
; bit equates
rp0 equ 5
;------------------------------------------------------------
org 0x000
;
start bsf status,rp0 ;switch to bank 1
movlw b'00000001' ;bit 0 = input
movwf trisa
movlw b'00000000' ;outputs
movwf trisb
bcf status,rp0 ;switch back to bank 0
movlw 0x04 ;0000 0100
movwf porta ;control word
call ser_in ;to serial input subroutine
movf rcvreg,w ;get data
movwf portb ;display data via LEDs
circle goto circle ;done
;------------------------------------------------------------
ser_in clrf rcvreg ;clear receive register
movlw 0x08 ;init 8 counter
movwf count
bcf porta,2 ;load shift register
bsf porta,2
getbit movf porta,w ;read port A
movwf temp ;store copy
rrf temp,f ;rotate bit into carry flag
rlf rcvreg,f ;rotate carry flag into rcvreg
decfsz count,f ;decrement counter
goto shift
return ;done
shift bsf porta,1 ;shift 1 bit
bcf porta,1
goto getbit ;again
;------------------------------------------------------------
end
;------------------------------------------------------------
;note: the 74HC165 gets shifted 7 times
;------------------------------------------------------------
;at device program time, select:
; code protection off
; watchdog timer disabled (default is enabled)
; standard crystal XT (using 4 MHz osc for test)
; power-up timer on
;============================================================

source : pic’n up the pace

Download PDF

SHIFT REGISTER

2009-06-12T00:59:00.004+01:00

Understanding about shift register is basic knowledge to understand serial communication.

To learn about shift register, we can use 74HC164 which is a serial in parallel out shift register. In and out are respect to the shift register. The project is to create and send 8 bit data to the shift register serially and looks is output via LED to see if the byte got there successfully.

Data to be send from microcontroller PIC16F84/A is initially defined and stored in a file register as 8 bits in parallel format. In order to convert them into serial format, the 8 bits in the file register are shifted left ( RLF ) one at a time. Bit 7 of the file register is sent on its way via a single output port line after each shift. The most significant bit is sent first because that is what the 74HC164 expects.

The 8 bits are marched out one at a time in succession.

The 74HC164 has 3 control line as the following :
Serial input
Clear ( clears output to 0’s ( normally High )
Clock ( Shift data trough bit 0 toward bit 7 )

To move data into the shift register, the first data bit is presented to the input. Then it is shifted in. The second bit is presented and shifted and so on.

Fig. Microcontroller PIC16F84/A with 74HC164

The shift register output are cleared on initialization as part of the power-on reset housekeeping so that all output will be low to start with.

;=======74HC164.ASM=================================4/25/97==
list p=16f84a
__config h'3ff1'
radix hex
;------------------------------------------------------------
; cpu equates (memory map)
porta equ 0x05
status equ 0x03
sendreg equ 0x0c
count equ 0x0d
trisa equ 0x85
;------------------------------------------------------------
; bit equates
rp0 equ 5
;------------------------------------------------------------
org 0x000
;
start bsf status,rp0 ;switch to bank 1
movlw b'00000000' ;outputs
movwf trisa
bcf status,rp0 ;switch back to bank 0
movlw 0x04 ;0000 0100
movwf porta ;control word
bcf porta,2 ;clear shift register
bsf porta,2
movlw 0x80 ;number to be sent
call ser_out ;to serial out subroutine
circle goto circle ;done
;------------------------------------------------------------
ser_out movwf sendreg ;save copy of number
movlw 0x08 ;init 8 counter
movwf count
testbit bcf porta,0 ;default
btfsc sendreg,7 ;test number bit 7
bsf porta,0 ;bit is set
shift bsf porta,1 ;shift register
bcf porta,1
rotlft rlf sendreg,f ;shift number left
decfsz count,f ;decrement bit counter
goto testbit ;next bit
return ;done
;------------------------------------------------------------
end
;------------------------------------------------------------
;at device program time, select:
; code protection off
; watchdog timer disabled (default is enabled)
; standard crystal XT (using 4 MHz osc for test)
; power-up timer on
;============================================================

source : pic’n up the pace

Download PDF

SERIAL IN PARALEL OUT 74HC595

2009-06-10T16:37:00.005+01:00

IC 74HC595 is a serial in parallel out that similar with 74HC164. The output will change state as data shifted in. This integrated Circuit has four control line as follow :
a. Serial input
b. Latch - shift register contents to latches
c. Clock – shift data MS bit first
d. Clear – clears shift register
Data is shifted in most significant bit first.

;=======74HC595.ASM=================================4/25/97==
list p=16f84a
__config h'3ff1'
radix hex
;------------------------------------------------------------
; cpu equates (memory map)
porta equ 0x05
status equ 0x03
sendreg equ 0x0c
count equ 0x0d
trisa equ 0x85
;------------------------------------------------------------
; bit equates
rp0 equ 5
;------------------------------------------------------------
org 0x000
;
start bsf status,rp0 ;switch to bank 1
movlw b'00000000' ;outputs
movwf trisa
bcf status,rp0 ;switch back to bank 0
movlw 0x04 ;0000 0100
movwf porta ;control word
bcf porta,2 ;clear shift register
bsf porta,2
movlw 0x80 ;first number to be sent
call ser_out ;to serial out subroutine
movlw 0x0f ;second number to be sent
call ser_out ;to serial out subroutine
bsf porta,3 ;register contents to latches
bcf porta,3
circle goto circle ;done
;------------------------------------------------------------
ser_out movwf sendreg ;save copy of number
movlw 0x08 ;init 8 counter
movwf count
testbit bcf porta,0 ;default
btfsc sendreg,7 ;test number bit 7
bsf porta,0 ;bit is set
shift bsf porta,1 ;shift register
bcf porta,1
rotlft rlf sendreg,f ;shift number left
decfsz count,f ;decrement bit counter
goto testbit ;next bit
return ;done
;------------------------------------------------------------
end
;------------------------------------------------------------
;at device program time, select:
; code protection off
; watchdog timer disabled (default is enabled)
; standard crystal XT (using 4 MHz osc for test)
; power-up timer on
;============================================================

source : Pic’n up the pace

Download PDF

MAKE A DELAY

2007-11-01T06:38:00.005Z

Delay is very important when we use microcontroller. Why? For example microcontroller PIC16F84/A that use 4 Mhz of clock, will executed instruction every 1us ( 1/1000000 second ). This is very fast.

If we want to make a led that connected to a port of microcontroller to blink, we must add a delay, otherwise the led can’t blink. This is because led blinking very fast and we see the led just lit.

How To Make a Delay?
Below is the easy way to make a delay. I want to introduce a software that can produce instruction to perform delay function for microcontroller PIC16F84/A (PICmicro family ). The software name was PICDEL made by Pier Paolo Messagio.

Figure 1 PICDEL

How to Use This Software
Fist we must inputting the Frequency that use by microcontroller ( in this case 4 MHz ).
Suppose we want to make a subroutine of delay for 1 second. We simply input 1000 in “Delay time(ms)” because 1 second = 1000 milisecond. After that we click “Calculate Cycle”. The software will appear Delay Cycle = 1000000.

Figure 2 Setting delay 1 second

Finally we just click “Generate Code” and the software will produce instruction to make subroutine of delay 1 second.

Figure 3 Instruction generated by PICDEL

Copy and paste instruction generated by PICDEL into your main program. Here is the example. We can add a label for easy understanding. Suppose we give a label “delay_1_second”.

delay_1_second ; this label additional by us
;-------------------------------------------------------------
; Code generated by PDEL ver 1.0 on 11/1/2007 at 1:24:31 PM
; Description: Waits 1000000 cycles
;-------------------------------------------------------------
PDelay movlw .14 ; 1 set number of repetitions (C)
movwf PDel0 ; 1
PLoop0 movlw .72 ; 1 set number of repetitions (B)
movwf PDel1 ; 1
PLoop1 movlw .247 ; 1 set number of repetitions (A)
movwf PDel2 ; 1
PLoop2 clrwdt ; 1 clear watchdog
decfsz PDel2, 1 ; 1 + (1) is the time over? (A)
goto PLoop2 ; 2 no, loop
decfsz PDel1, 1 ; 1 + (1) is the time over? (B)
goto PLoop1 ; 2 no, loop
decfsz PDel0, 1 ; 1 + (1) is the time over? (C)
goto PLoop0 ; 2 no, loop
PDelL1 goto PDelL2 ; 2 cycles delay
PDelL2 clrwdt ; 1 cycle delay
return ; 2+2 Done
;-------------------------------------------------------------

Finally into main program we must add some instruction as below.

PDel0 equ 0CH ; location of RAM (PIC16F84/A)
PDel1 equ 0DH ; location of RAM (PIC16F84/A)
PDel2 equ 0EH ; location of RAM (PIC16F84/A)

Figure 4

Download PDF

UNDERSTANDING THE REGISTERS

2007-10-31T00:07:00.005Z

What is the register?

Register is a memory inside of microcontroller that have a specific function. Register can be read read from or written to. By written to the register, mean we are still controlling some function of the microcontroller. For Example, Port A controlled by 2 register. There are register PORTA and register TRISA. More complex a microcontroller, more register needed to control inside the microcontroller.

Microcontroller PIC16F84/A have several registers. There are divided into 2 location called Bank. Bank 0 and Bank 1. Bank 0 is use to manipulate data and bank 1 is use to control the actual operation of the microcontroler. To change location from Bank 0 to Bank 1, simply by change bit RP0 ( bit 5th of register STATUS ).

RP0 = 0 --> Goto Bank 0
RP0 = 1 --> Goto Bank1

Figure 1 Registers of PIC16F84/A

Here is some information about the register on microcontroller PIC16F84.

W Register

W Register is a "Working" Register. On another type of microcontroller usually called as "Accumulator". This register is common register to use in arithmatic operations. We can put any value on this register. Also we can moved it's content to another registers. We can also add the content of W register with another value and save in the same register. W register doesn't have address.

PORTA Register
PORTA have address of 05H ( hex ). PORTA is a register that control port A. To make one of output pins high on port A, simply by send "1" to corresponding bit on PORTA. To make one of output pins low on port A, simply by send "0" to corresponding bit on PORTA. Port A is a 5 bits wide. Each line have a name, there are RA0, RA1, RA2, RA3, and RA4. RA4 also have another function for input to Timer/Counter.

1 --> PORTA ---> port A High ( +5 Volts )
0 --> PORTA ---> port A Low ( 0 Volt / ground )

PORTB Register
PORTB have address of 06H ( hex ). PORTB is register that control port B. To make one of output pins high on port B, simply by send "1" to corresponding bit on PORT B. To make one of output pins low on port B, simply by send "0" to corresponding bit on PORTB. Port B is a 8 bits wide. Each line have a name, there are RB0, RB1, RB2, RB3, RB4, RB5, RB6, and RB7. RB6 also use as "Clock" input during programming. RB7 also use as "Data" input during programming.

1 --> PORTB --> port B High ( + 5 Volts )
0 --> PORTB --> port B Low ( 0 Volt / ground )

TRISA Register
TRISA have address of 85H ( hex ). This register have functions to control the direction of port A. With this register, we can assign port as input port or output port. To become input port, simply by send "1" to corresponding bit on TRISA. To become output port, simply by send "0" to corresponding bits on TRISA.
On Port A we have 5 pins ( lines ) hence 5 bits.

1 --> TRISA -- > Input Port
0 --> TRISA --> Output Port

TRISB Register
TRISB have address of 86H (hex ). This register have functions to control the direction of port B. With this register, we can assign port as input port or output port. Just same as port a with TRISA. On port B we have 8 pins ( lines ) hence 8 bits.

1 --> TRISB --> Input Port
0 --> TRISB - > Output Port

For Example we want Port B have direction as Follow. RB0 ~ RB3 as input port and RB4 ~ RB7 as output port. So we must assign TRISB with the value of :

RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0
out out out out in in in in
0 0 0 0 1 1 1 1 Binary

or 0F H (hex )

Another example we want Port A have direction as follow. RA0 = input, RA1 = output, RA2 = input, RA3= input and RA4 = output So we must assign TRISA with th value of :

RA4 RA3 RA2 RA1 RA0
out in in out in
0 1 1 0 1 Binary.

or 0D H ( Hex )

STATUS Register ( Address : 03 H )
STATUS Register have many functions. But, for this time we just want to explain functions of STATUS register to change from Bank 0 to Bank 1 or vice versa. Bit 5th of STATUS Register is Bit RP0. This bits togeter with RP1 is use to control Bank.

Bank Location Bit RP1 Bit RP0
Bank 0 0 0
Bank 1 0 1

From above explanation, we understand that only bit RP0 is used to control bank selections. Because there are only 2 Banks so bit RP1 not use ( keep "0" ).

Bank Location Bit RP0
Bank 0 0
Bank 1 1

An Example Code
We want to make Port A as input port and Port B as output port.

Here's the code.

bsf STATUS,RP0 ; bit set RP0 ( make RP0 = 1 ) to go to Bank 1
movlw b'11111' ; RA0 to RA4 --> "1" for input port
movwf TRISA ; copy contetn W register to TRISA register

movlw b'00000000' ; RB0 to RB7 -- > "0" for output port
movwf TRISB ; copy content of W register to TRISB register

bcf STATUS,RP0 ; bit clear RP0 ( make RP0 = 0 ) to go back to Bank 0

Download PDF

2007-10-30T01:24:00.008Z

CONTROLLING THE PORT OF PIC16F84

Preface

Microcontroller capable to control everything. The limitation is how we can write program for microcontroller. The program is an instruction that send to microcontroler and will be save on ROM ( Flash Memory ) on the microcontroller. Microcontroller will do as exactly as the program.
Below is the Work Flow of microcontroller.

Figure 1. Microcontroller’s work flow

Microcontroller will receive signal from input line and will processed this signal base on program on it’s Flash memory. After finished processed, it will send signal to the output line. In actual conditions, microcontroller have ports that can be made as input ports or output ports. Microcontroller ports normally called as I/O ports.
As the name of I/O ( Input/Output ) ports, each port have a bi-directional capability that’s mean each port individually can be input port or output port.

Figure 2 Two Ports of the PIC16F84

PIC16F84 have 2 ports that have bi-directional capability on each line. Port A have 5 lines named RA0,RA1,RA2,RA3,RA4. Port B have 8 lines named RB0,RB1,RB2,RB3,RB4,RB5,RB6,RB7.

Figure 3 Name of each port on Port A and Port B

Controlling the Port
Before we can use the port, we must tell to the microcontroller which port as input port and which port as output port. To do so, we must understand register that controlling the port.

List 1 Register that controlling the port
Register Name Purpose Address
PORTA Content of Port A 05 H
TRISA Direction of Port A 85 H
PORTB Content of Port B 06 H
TRISB Direction of Port B 86 H

Note :
A “1” on PORTA / PORTB means that the line has “High Logic” or +5 Volt.
A “0” on PORTA / PORT B means that the line has “Low Logic” or ground ( 0 Volt)

A “1” on TRISA / TRISB means that the line become “Input Line”
A “0” on TRISA / TRISB means that the line become “Output Line”

Suppose we want to make condition on PORTA as follow.
RA0 = input line
RA1 = output line
RA2 = input line
RA3 = output line
RA4 = output line

Figure 4. Example Conditions of PORTA

To make that conditions, we must adjust register ( using instruction as stated on assembly language ) as follow.

;--------------------------------------------------------------------------
; program name : sample.asm
; by : your name
; date :
;--------------------------------------------------------------------------
processor 16f84 ; to tell the compiler , processor used

porta equ 05h ; equivalency porta = 05h
trisa equ 85h ; equivalency trisa = 85h
status equ 03h ; equivalency status = 03h
rp0 equ 05 ; equicalency bit rp0 (inside status ) = 05

org 0h ; start program locations

initialize
bsf status,rp0
movlw b’00101’
movwf trisa
bcf status,rp0

next
bla…
bla…

This instruction will make microcontroller same as what we want. Here’s the explanations.

a. Instructions : bsf status,rp0 ; ( register = status, bit = rp0 )
This instructions mean “bit set file register”
The bit in that instruction is “rp0” ( bit 5th of register status )
This instruction make us will go to Bank1 to allow change TRISA register

b. Instruction : movlw b’00101’
This instructions mean “move literal to W register”
This register will make W = 00101 B (Binary)

Why we use b’00101’ ? This is as we want to control port a directions!

RA4 RA3 RA2 RA1 RA0
Output Output Input Output Input
0 0 1 0 1

c. Instruction : movwf trisa
This instruction will copy content of register W to TrisA
After executed trisa will content = 00101B (Binary)

d. Instruction : bcf status.rp0
This instruction mean “ bit clear file register” in that case bit rp0 in the register status will be cleared to low (“0”). This instruction will make us go back to Bank 0 after chang trisa register.

The same action also can be done to PORTB and TRISB

Download PDF

How to Make Programmer PIC16F84

2007-10-24T11:10:00.004+01:00

Preface
One of the type of famous microcontroller around the word is PICmicro microcontroller manufactured by Microchip Inc of the U.S. Even though there are so many kind of microcontroller under PICmicro family, the PIC16F84/A is the best one for beginner to understand PICmicro family microcontroller.

PIC16F84/A Microcontroller
Actually PIC16F84/A is not the best microcontroller under PICmicro family, but some feature of the microcontroller made easy to programming the microcontroller it self. Only use small part, we can simple build programmer for microcontroller. Compare with other microcontroller like Atmel 89C51 that need some complex circuit for programmer.

This is because PIC16F84/A use “Flash” technology for their Program Memory. We can program and erase up to 1000 times even more! Below is the list of some good feature of the PIC16F84/A microcontroller :

Capacity of Program Memory is 1024 ( 1K ) x 14 on Flash Memory
RAM capacity 68 byte
Data Memory on EEPROM 64 byte
Have 13 I/O divided into 2 ports ( Port A = 5 bits and Port B = 8 bits )
Only have 35 instruction due to RISC-type computer
Have Timer 8 bit with Pre-scaler facility
Watch dog Timer with it’s own internal oscillator
All I/O ports can direct drive for LED
Allow In Circuit Serial Programming (ICSP)
Only have 18 pin count on the DIP package format

Figure 1. Microcontroller PIC16F84/A

All of the feature of microcontroller PIC16F84/A make this microcontroller best for beginner. After understanding this microcontroller, somebody can study other microcontroler such as PIC16F88, PIC16F877/A etc.
Pin Diagram of Microcontroller PIC16F84/A
Micro controller PIC16F84/A come with 18 pin, this small foot print make this micro controller easy to “embbed” to our project.

Here is the pin diagram of PIC16F84/A.

Figure 2 Pin Diagram PIC16F84/A

To explain about the each pin functions, first we will separated pins of some category.
Power
a. Vdd : +5 Volt for Micro controller
b. Vss : ground

System
a. MCLR : Master Clear ( Reset ) active low for microntroller. Normally pull up with 10K resistor to Vdd. Vpp ( Programming Voltage ) during programming

Oscillator
a. OSC1/CLKIn : Input Osc or pin for XTAL/Resonator
b. OSC2/CLKOut : Output Osc or pin for XTAL/Resonator

Port A
a.RA0 through RA4 (TOCKI = input for Timer Module)

Port B
a.RB0 ( input for INT = interrupt facility )
b.RB1 through RB5
c. RB6 ( Input Clock during programming)
d. RB7 ( Input Data during programming )

How to Use Microcontroller?
Before you can use microcontroller for your purpose, first you must make a programmer. The programmer is to “download” instruction to the chip. One of the simple programmer given below.

Figure 3 Circuit of Progammer PIC16F84/A

This programmer is connected to Serial Port ( COM port ) of the PC ( Personal Computer ). Yes,..this is simple programmer, but it’s work! We just need some component such as 7805 ( voltage regulator for 5 Volts ), Capacitor, Diode and several resistor. Even we can delete the LED. After we assembly this circuit, don’t forget to use project box for professional ’s looks

Figure 4 Sample of PIC16F84/A Programmer with ZIF Socket

The Software
To become useful, programmer PIC16F84 must have a software associated that run on PC. For this purpose we can use PicProg as shown on below image.

Figure 5. PicProg

How to use this software?

1. Open picprog by clicking it’s icon.
2. Click “open” button and select file that want to download to microcontroller (file must have extension .hex )
3. Select Oscillator ( RC,XT etc ) based on our oscillator use
4. Select Configuration ( normally Power Up Timer ) see Fig.5
5. Serial port will be choose automatically
6. After that, simply click “Program” button
7. After this moment, program ( *.hex ) for microcontroller will be transferred to microcontroller.
8. Microcontroller are ready to be use.

Besides of this operation, Picprog still have other useful button.
a. Read button. This button use for read the content of microcontroller
b. Erase button. This button use for erase the content of microcontroller.
How to change EEPROM Data?
Simply double clicks on EEPROM data and change the content ( default content are FF)

Make file Hexa
In order to program microcontroller,we need a file that have extension .hex. How to make it? Fist we must write our program use editor text such as Notepad. Save file and give extension .asm ( assembler ). After that compile that file using MPASMWin.

Figure 6. MPASMWin

Use this software as follow :
1. Click on button “browse”
2. Find the right file ( *.asm )
3. Change processor type to PIC16F84
4. Other set as default
5. Click “Assemble”

If error occurred, file *.err will be generated. Open this file using Notepad or other text editor software. And fix the problem.

Figure 7. Result MPASM OK

Figure 8. MPASM Error

Download PDF