I am K.G. Pasan Laksiri Karunanayake. Citizen of Sri Lanka and Resident of Colombo.
I have many years of Practical and Professional experience in advanced microcontrollers and product developing.
Highly trained under Arthur C. Clark Institute of Modern Technology in Microcontrollers, Hand Held Devices, Mechatronics and Electronic Equipment Repairing.
I am the proprietor of OptoElectronics.lk. OptoElectronics is an innovative and research based organization. Engaged in manufacturing and supplying world class digital display boards and digital clocks widely used in all types of industries for varied applications.
Our Product Range
Our product portfolio includes Moving Message Displays, Token Display units, Production Displays Boards, Multi Line Tri-Color Message or Video Wall Displays, Rental Video Screens, Currency and Interest Rate Displays, Digital Counters with Natural Voice ( Sinhala, Tamil and English ), Wireless or Network based Digital Master Slave clocks and etc.
Our Quality
We are a quality driven manufacturer with all our efforts focused on achieving complete customer satisfaction. We constantly maintain a superior quality in all our product range and successfully won the trust of our customers.
Our Team
We have highly skilled dedicated team of individuals , who work hard to provide the best range of display products and service to our customers. Our team comprises of Electronic and Electrical Engineer, Software Engineer, Well Experienced Management staff and Skilled labors.
Our prime concern always remain to provide our customers the quality product with diverse customization facility we constantly work on it to provide more and more customer satisfaction.
Our Clients
Some of our leading clients includes :
- Loadstar (Pvt) Ltd.
- David Peries Motor Company Lanka Limited.
- Jafferjee Brothers Exports (Pvt) Ltd.
- HSBC
- SLECC
- Systech Solutions.
Contact Us
OptoElectronics.lk
No. 461/6, Weili Road, Thalawathugoda. Sri Jayawardenapura Kotte.
Mobile – 0777 248 936
Email – pasanlaksiri@gmail.com
hello pasan, i’m kushan. and i’m an instructor at german tech. pasan your projects are great. are u using eagle for your pcb’s. how do you print the top component side.
and i,m very interested in your led sign board project. are u using assembler language or a high level language to write down the program. if you can give me some information it will be grateful of you.
kushan
By: kushan premarathna on March 11, 2010
at 9:27 pm
Hi Kushan, Yes I use C language. I am pretty lazy to play with assembly.
Coz its take more and more time which that I don’t have. No, I actually don’t like EAGLE. I use Sprint-Layout5 and I am about to change cad soft to Altium Design.
The PCBs are done by using crappy screen print method. Top is also done by screen print.
What other info that you need kushan.
Bye!
By: pasanlaksiri on March 11, 2010
at 9:44 pm
pasan,
thanks for your information. I’m using eagle. i downloaded the sprint-layout 5. can i draw the schematic on that software. didn’t knew about altium. i visited the site. i think it’s a great cad software. I’m downloading it now.
from where did you designed your screen print layout.
i made a 8x 10 led sign board using shift registers(4094) to multiplex columns. but in that method more columns couldn’t be build coz the duty cycle for each column is getting low. and the brithness too. i used 5 registers to hold a each character, and when need to shift i shifted the
register values from each register to the next register. u used the ht 1632 to your sign board.
on that ur multiplexing the rows isn’t it. so how are shifting the text are u shifting the registers or each bit from a register to the next.
can you please give me some info about it.
kushan..
By: kushan on March 13, 2010
at 11:08 am
” from where did you designed your screen print layout. ”
my self.
” u used the ht 1632 to your sign board. ”
No dear
. 8X64 one is built by just using shift registers (74hc959) . same as you are. Im a huge fan of 74hc595 
. And I also used driver ICs instead of driving transistors coz transistors take lots of space. I hope to use Holtek display drivers for larger displays. But cascading PICs also a nice solution. Like 4 blocks per PIC. and another Master PIC for feed data.
Hey your using which language ?
What I am doing is column scan. I use shift registers to select a column. and then feed the data. Only difference is im only using one 8bit port and another 2 port pins. Thats called “macmux”. Plz see this image
http://pasanmicroprojects.files.wordpress.com/2010/03/k8lh-7×55-c2b5sign-concept.png
My design is also same above. And I also maintain a 8bit X8 video buffer. Well I am using C language so I easily can use single 64bit buffer. But it will also effect the system performance. Thats why I use 8 of 8bit buffers.
By: pasanlaksiri on March 14, 2010
at 12:00 am
pasan,
how did you make your screen print with your self.
didnt you made it from a printing shop.
i write with assembly, and pic basic pro.
in the sign board,( image) how do you control the rows and the columns by same pins.?????
are you using the shift registers to select columns or load data. i’cant understand how the program is written according to the schematic.
please help
By: kushan on March 17, 2010
at 7:15 pm
” how did you make your screen print with your self ”
Little hard but easy. Its just not rocket science. Just see some you tube videos about Screen Print. And you can get all the things that you need from Nelu’s Advertising Nugegoda.
” didnt you made it from a printing shop. ”
No by my self. I want the best quality.
“how do you control the rows and the columns by same pins”
Easy. did u see those are shift registers with latch. I think you can guess now.
” are you using the shift registers to select columns or load data. ”
Yes select columns. I do Horizontal Scan. ( Column Scan )
“i’cant understand how the program is written according to the schematic.”
Just for get the schematics and study 74HC595.
At the very first time that I saw the schematics I didn’t even get a clue.
By: pasanlaksiri on March 17, 2010
at 10:24 pm
Hi Passan
I’m very impressed about your work
Wishing you a Very Good Luck !!!!
keep this blog up Bro.
Anuradha
By: Anuradha Fernando on April 13, 2010
at 10:21 pm
Thank you very much Anuradha.
By: pasanlaksiri on April 13, 2010
at 10:25 pm
hello sir
i like to learn all about digital electronic & micro controllers
can u help me please?
is there have any books or sites ?
please kindly give me those things
i’m doing mobile phone repair (software & hardware). so i think i can learn it ..
thanks
bye
By: dilam silva on April 23, 2010
at 10:36 pm
Hi dilam. Where are u living. There are tons of books for microcontrollers. Plz give me some time to select some perfect books for you. I just can say google it. But i know thats not what you expect from me.
Where are u doing ur Phone Repair course.
By: pasanlaksiri on April 23, 2010
at 10:53 pm
don’t forget ok????
By: dilam silva on April 23, 2010
at 10:37 pm
i’m at ganemulla
i followed a course 3years before & now i have a mobile phone repairing center @ gampaha…
doing this business morethan 2 years
thank you for ur kind reply & please guide for mircro controller
& tell me whats the requirements for learn it
thanks
bye
By: dilam silva on April 23, 2010
at 11:04 pm
requirements – well ur repairing mobiles phones. So i think you have good knowledge about basic electronics. Thats what mainly needed.
Do u know any programing languages. Like C,Pascal,assembly?
I’ll select you some books thats start from the basics.
And it will speed up if u join some class.
By: pasanlaksiri on April 23, 2010
at 11:52 pm
sorry for bad typing i’m dilan silva
By: dilan silva on April 23, 2010
at 11:05 pm
thank you for ur kind rely…
actually i have basic knowledge about electronic but i don’t know about programming languages..
can u please suggest me easier programming language working on win xp
if u select a laguage i can follow that
but the proble is , i can’t go to class becoz i always busy with my business 7 days open 9.00am to 8.00pm
after comming home, again repairing 10.00pm to 3.00am after i going to bed & getup again 8.00 am
in these days i came to home & trying to learn about micro controllers b’coz of my please
& if u suggest me some books & softwares, program i can brought & try that
i hope u’ll understand my situation
By: dilan silva on April 24, 2010
at 12:05 am
hello sir r u there?
did u select some books for me?
if u r busy its ok… if its not, then please do this for me. i’m very thankful for that ok
bye
By: dilan silva on April 24, 2010
at 9:41 pm
Hi, Dilan plz give me little more time. I extremely busy these days. Lots of guys e-mail me and asking many questions. So i also have answer to those questions.
And I just can pick some books and recommend those. Coz it must be perfect for you.
By: pasanlaksiri on April 24, 2010
at 10:42 pm
ok sir i can understand ur situation. & i don’t like to force u
if u have any free time, please help me ok?
if u have any problem regarding mobile phones repair section, just send me a mail .. i’ll help u ok?
thanks
bye
By: dilan silva on April 24, 2010
at 10:51 pm
Sure bro.
Thank you very much for the offer.
By: pasanlaksiri on April 24, 2010
at 10:53 pm
welcome & good bye still have many phones to repair in my bag … ok now i’m leaving
good night
By: dilan silva on April 24, 2010
at 10:54 pm
Hi, This book is perfect for you. Microcontroller Programming: The Microchip PIC
Download link. No Pass. http://rapidshare.com/files/19478497/CRC.Press.Microcontroller.Programming.The.Microchip.PIC.Dec.2006.eBook-BBL.rar
Its starts form the very beginning. And its also use PIC16F84A chip. Its dead old but it will help you to speed up your learning process. Please download PIC16F84A Data sheet. Always refer the data sheet. And don’t try to read read the data sheet A to Z. Its useless.
And also u need a programmer to program the chips. Try to build this http://feng3.cool.ne.jp/en/pg5v2.html
Or its PCB is available at pettah for few bucks.
Bye
By: pasanlaksiri on April 26, 2010
at 11:20 pm
thank you verymuch sir for ur kind reply
sir someting wrong with the rs link please can u check the link again please
thanks again
By: dilan silva on April 26, 2010
at 11:36 pm
Looks like its deleted by RS.
New link http://rapidshare.com/files/123387838/Microcontroller_Programming_-_The_Microchip__PIC.rar.html
If its ask for pass plz use this >> mbandala
By: pasanlaksiri on April 27, 2010
at 12:25 am
Hi. pasan,
I went through ur work and im realy impressed. good luck.
And im a Soft engi. undergraduate. But i love electronics and especially embedded systems.
i hv desinged sm SMS controlled systems from pics.
and like to learn unknown stuff from you.
Hope u will help me.
thank you.
my favorite is development board and dotmatrix 1. im very curious about dot matrix . i tried to build a one but fail. so im hoping to seek ur great knowladge.
thank you
By: Sakvith Jayasinghe on May 13, 2010
at 10:31 pm
SMS control. Did u use a mobile phone or original GSM module.
By: pasanlaksiri on May 13, 2010
at 10:39 pm
Yp. a original GSM module SIM300. had difficulties in finding da correct datasheet. but now working like a charm.
Pasan , i need to get sm advice in screen printing 4 urgent pcb matter.
Is it ok to call u or email. what would u prefer.
pls help
thanx
By: Sakvith Jayasinghe on May 14, 2010
at 5:09 pm
What do you want to know about screen print ?
You didn’t bought SIM300 from here right. How much did it cost you.
Im also looking for order few serial GSM Modules.
Bye
By: pasanlaksiri on May 14, 2010
at 5:27 pm
Screen print: what matirials do u need i have a frame. but mesh dpi? emulsion and other stuff i need? specially the ink?? for print in copper board.
nope from a friend. but u can get it from ebay cost about 2500++
http://cgi.ebay.com/SIMCOM-GSM-Module-SIM300-CZ-connector-/250627804654?cmd=ViewItem&pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item3a5a94cdee
this is da exact 1 i used.
pls help me on screen print.
is its not a hassle 4 u i can call u and get advice
thank you.
By: Sakvith Jayasinghe on May 14, 2010
at 5:42 pm
Sure bro. Could you call me like around 6.30pm.
I bought all the screen print parts from Nugegoda Nelus Source One. The mesh is 140. They have two inks PVC and SS. SS ink is perfect for our work. its pretty thick and taking little more time to dry. Days like these it will take like more than 12 hours to dry. PVC ink is quick dry. But on the other hand it will coat very thin layer.
For screen nelus guys do exposing stuff too. So what you all have to do is. Show your art work to them and tell them I want a screen for this and I want it to be exposed.
For a new screen ( like 10*12 inch) and expose it will cost you roughly 1400/=
Hey but do u know about pnp papers. ( press and peel )
By: pasanlaksiri on May 14, 2010
at 5:58 pm
Oh.. good. i will go thr. thanx.
Yp. hv used once. culdnt find in in nugegoda and pettha so brought it from ebay cost about 600. 2A4 sheets. its bit expencive. but good quality. print. have built a surface mount pcb for gsm.
but i do general toner transfer from sticker sheet.
but not good for large pcb’s
do u have any options??
ahh i thot u do the emultion apply to the mesh.
but i think we xan also do the expose from halogen bulb.
By: Sakvith Jayasinghe on May 14, 2010
at 6:15 pm
Its just need some even UV source. Normal Tube Lights will do the job. My light box have six 12inch tube lights. It isn’t easy as u said it is. Really long process. First you have to roughen the mesh using abrasive degreaser gel. Then dry it. Then you have to coat a very thin even layer of UV sensitive gel ( im using nelus ready made stencil emulsion ink ). Then expose appropriate time and wash. ( expose time is depend on ur art work )
But bro 300/= for a A4 sheet is pretty cheap. Why go for screen print. Actually for a single PCB screen print is too costly.
By: pasanlaksiri on May 14, 2010
at 7:00 pm
Yp. yp. it take 15 day to arrive to srilanka. thats da prob.
No i need to make 50 same pcb’s dats y i asked for it.
toner transfering 4 50 s not easy.
what about photorisist copper board??
By: Sakvith Jayasinghe on May 14, 2010
at 7:26 pm
hello do you know make for me some pcb ? now and in the future ? now I need 10 pieces
I am living in UK
thanks Marian
By: jpucik on May 14, 2010
at 7:29 pm
Hi Marian.
Double layer PCBs or what ? Is your PCBs full of SMD parts ?
By: pasanlaksiri on May 14, 2010
at 8:00 pm
Ahh and there s my friend. he do pcbs about 300 for 5×5 board fully compleated. 500 for dual side. very professional. i do from him for complex boards.
at home for prototypes.
By: Sakvith Jayasinghe on May 14, 2010
at 7:31 pm
There are lots of guys out here doing PCB making stuff. actually 300 for each is too much for 50Pcbs. For double layer PCB if u wanna do ti right u must at least have to do 4 screen prints.
Is that 300/= is with top layer and drilling.
By: pasanlaksiri on May 14, 2010
at 7:58 pm
nope. only drilling and surface mount.
in toner transfer i only cost 20 + copper board. only for stiker sheet.
ur a sayn dat 300 s too much 4 a 5×5 bord???
ahh nono not 300 4 each only 4 one..(not bult)
didnt ask a price 4 50.
By: Sakvith Jayasinghe on May 14, 2010
at 9:54 pm
Sory again where did u buy that HT1632? f
By: Sakvith Jayasinghe on May 14, 2010
at 10:01 pm
From http://www.sureelectronics.net/
actually I bought HT1632C bare chips too for $4 each
By: pasanlaksiri on May 14, 2010
at 10:54 pm
respected sir i’m vinoth,i am electrical & electronics engg.,i want to do a project,i have much interest in dot matrix display please help me about the connection and and how to do the project
By: vinoth on May 28, 2010
at 10:33 pm
I did it by using PIC MCU. So how about your knowledge about programing and electronics.
By: pasanlaksiri on May 28, 2010
at 10:38 pm
oyage msg display ekata aluth massege ekak program karane komada
thanks
By: Manjula on May 29, 2010
at 11:33 pm
At the time im just by using the PC.
But I hope to use PS2 keyboard. So no need any pc to edit the TEXT.
By: pasanlaksiri on May 30, 2010
at 4:36 pm
oyage msg display ekata use karpu pic ic eka 16f877a da ?
By: Manjula on May 30, 2010
at 8:49 pm
Yup 16F877A.
By: pasanlaksiri on May 30, 2010
at 8:55 pm
ayye,oya electronic engineer kenekda natnam hobby ekatada me wage advance electronics projects karanne,mat asai pic gana gaburata igenaganna.oya class karanawada ?
By: Manjula on June 1, 2010
at 10:41 pm
ayye,tawa eka prob1k tiye,pitaratin ic 1k 2k genna ganna hodama widiya mokakda ?
By: Manjula on June 1, 2010
at 10:45 pm
Malli, I am not an engineer. But I am born with it.
Also I have long time experience.
If you want to learn I know a perfect guy for you. But it will cost you. Is it ok ?
Malli if you wannt to import few chips ebay is perfect. Coz shipping cost is low. But eBay sellers may not have any uncommon slow selling chips.
But in here there is a joint near Gangarama Temple. There name called Orel Solutions (PVT) Ltd. Actually its a part of ORRANGE ( PVT ) Ltd.
You can order any item from them. But the price will be little high. They are importing from Farnel UK Store.
Click below link to see Farnel Sri Lanka local agents details
http://www.farnell.com/distributors/srilanka_osp.htm__There contact details__
Orel Solutions (PVT) Ltd
No 49, Sri Jinarathana Road,
Colombo 2.
Sri LankaTel: +114 792103 / 105
Fax: +115 376678
Email: priyashantha@os.lk
Btw malli I am importing directly from manufacturers site or from direct china agents. Because its cheap.
By: pasanlaksiri on June 1, 2010
at 11:06 pm
dear big brother,
godak thanx ayye oyata mata dunnu information walata hari,orel solution walin man badu gennagena tiye,tikak gana tama wadi neda ? e-bay walin hari directly manufacturergen hari oya badu genna gannakota pay karnne credit card1enda? card 1en pay karana1 internet1di safe na kiyala ape thaththa kiyanawa,eaka attada ? safe nam mata thaththage card eken badu genna ganna puluwan.ane a ganat advice1k dennako tara natiwa hode.
By: Manjula on June 2, 2010
at 9:09 pm
Malli we cant say paying via credit cards is unsafe. Even is SL lots of people using credit cards for on line payments.
I think you better use Sampath Bank WEBCARD. Its like a Pre Paid VISA card.
Oyata thiyenne Tranfer karanna oona gana witharak WEBCARD ekata dala. WEBCARD eken gewanna.
By: pasanlaksiri on June 2, 2010
at 9:22 pm
pasan ayya,
thank you very very much ayye oyata! a wagema oyage danuma tawa tawa diunu karaganna labewa kiyala mama prarthana karanawa ! aluth gadget 1k hadala market karanna adahasak natida ?
By: Manjula on June 4, 2010
at 9:53 pm
Hi Pasan,
I am deeply impressed with your work. I just happen to land on to your site searching something. Its really great that you are prepared to help others as well.
I shall email you separately.
Rajesh Bij
INDIA
By: Rajesh Bij on June 9, 2010
at 11:57 pm
Thank you very much for your kind comment Rajesh.
By: pasanlaksiri on June 10, 2010
at 12:02 am
SRI LNAKAN. as written in About Me.
Please check if it should be SRI LANKAN.
Is it a typing mistake or is some style of writing?
By: Rajesh Bij on June 17, 2010
at 9:46 am
By: pasanlaksiri on June 17, 2010
at 9:51 am
Have you worked with GPRS modem to send data to a server with static IP address, if yes, I have some issues to discuss.
By: Rajesh Bij on June 17, 2010
at 9:48 am
Nope, have not try any gprs modems yet.
By: pasanlaksiri on June 17, 2010
at 9:52 am
Hi MR.Rajesh,
Please refer this document for AT commands.
http://www.semiconductorstore.com/pdf/newsite/Telit/Easy_GPRS_Guide.pdf
Regards
Mali
By: Mali on June 17, 2010
at 8:30 pm
Lovely. Thanks.
Im trying to use nokia3310 wich do not support AT Commands.
By: pasanlaksiri on June 17, 2010
at 9:24 pm
What about F-Bus with Nokia 3310.
Look at this..
http://www.embedtronics.com/nokia/fbus.html
No link till now..
By: Mali on June 17, 2010
at 10:01 pm
Yes Full Duplex F-BUS. Thats what im trying to do. Thanks for the link
By: pasanlaksiri on June 18, 2010
at 9:02 am
My pleasure Mr.Pasan
Bye
By: Mali on June 18, 2010
at 3:11 pm
Hi Pasan,
Great to arrive to your site. I tried to build one of your project, home made digital tachometer. My problem is I am a beginner with PIC, just get the inspiration from your project, I cant get the 16f84 in my place. There are only 16f84a. How can I modified the hex code to meke it possible to run on 16f84a. Please advice.
Thank you.
By: adi on June 21, 2010
at 11:48 pm
Thanks for the comment. The thing is I cant even fnid a data sheet fro 16f84. Is your code in Assembly or C. If its in C which compiler do u use. U better use 16F628A atleast. There is no way to edit the hex code. You must need the Source Code.
By: pasanlaksiri on June 25, 2010
at 8:02 pm
Pasan aiya. i hv sent u an email.. please read it if you have time.
thank you.
By: Sakvith Jayasinghe on August 1, 2010
at 11:01 pm
Check your maills now.
By: pasanlaksiri on August 2, 2010
at 8:13 am
Your site is *phenomenal* and you are a prolific creator of interesting stuff! I wish I had the time and resources as you have to create all these stuff!
See you around, buddy! Good Luck with your future endeavors.
//seemanta
By: Seemanta Dutta on August 14, 2010
at 1:33 am
Hey dear,
My god I saw your blog few months back. I also comment on it. I’TS AMAZING
Thank you very much for your kind words its so much to me.
By: pasanlaksiri on August 14, 2010
at 8:26 am
Hay bro,
Your works are awsm.
By: Viduruvan on September 2, 2010
at 9:15 am
thank you for your information sir.
I learn pic too. and your web help me
for 12f675 project.and may be you can guide line my
function
i/p1 = analog 0-0.99 v.
i/p2 = analog 0-0.99v.
Vref = 0.99 v. (i think reference by software)
condition function
i/p1 = i/p2 ; o/p gp3-6 = 0 (digital)
i/p1> i/p2 : o/p gp3-6 = 1
i/p1 < i/p2: o/p gp3-6 = 0
can you guide line my project sir
please help…….
By: Tachakorn on September 5, 2010
at 1:33 am
hi pasan
u r verry interlegent man
By: chaminda on September 12, 2010
at 6:12 pm
hello sir..im luqman from malaysia..i just read ur interesting blog..it so great to see ur project
but i need ur help..cpuld you spend time to do a program?currently im a diploma student..i got to do mini project that is Smart Fire Detector..i need to create a program in C language that use PIC18F8720..can u help me?
i attach with simple project background as well
PROJECT BACKGROUND AND SIGNIFICANCE
Current situation and reason for making the project.The reason of making this project because is detect fire burning and to avoid rapid fire burning by using ventilated fan.
The fans monitor temperatures from several sources. By properly configuring speed fan, we can let it change fan speeds based on system temperatures. When choosing parameters for the minimum and maximum fan speed, we are using different temperature level to decide whether to on one or two fans. Consider that when the WARNING temperature is reached, the program sets the IC to run both fans.
if you can create the program it will be grateful of you.
By: luqman on September 17, 2010
at 7:24 am
I have built a moving sign around 89v51rd2 with ps2 keyboard interface to enter the required message.
I am not using any shift registers or ULN2003 kind of thing
Matrix is 7 x 64, or 7 x 96
Sending codes at rows and enabling one column at a time using s/w .
My concern is the brightness. It is very less, I saw your displays are highly bright.
I understand duty cycle is the main culprit. In this is it is 1/64 or 1/96
Suggest how can I get more brightness, and
what is the duty cycle with your displays?
Please help
By: Rajesh Bij on October 13, 2010
at 11:50 am
[...] About Me Posted by: pasanlaksiri | January 2, 2011 [...]
By: 2010 in review « PicTronics on January 2, 2011
at 5:34 pm
Its Really a great job….!
What are U doing now?
Are you working somewhere full time?
Do u have any plans to do business. Local & International.?
If yes, feel free to call me on 0777569994
Regards.
Sumedha.S
By: Sumedha on January 18, 2011
at 1:44 am
No I am not working any where.
By: pasanlaksiri on January 23, 2011
at 9:20 am
hello sir u r great. please give me the circuit diagram of matrix 8×64 sign board. plzzzzzzzzzzz
By: ravinder on January 30, 2011
at 10:35 am
I´m looking for sensei master to show me how to led´ing everything. I´m from mexico very enthusiastic on electronics. I work a component level circuit repair at a pc repair shop. The this is I want to get fully into led sings for my on business. Will you mr. Pasan helpme? I´m already reading some good recommendations you have posted in this forum…
++I have MPLAB installed.
++a 3mm 12x36inch MDF table whit a 16×48 led matrix all soldered fly wire style (all i know till today)..
++a pic burner like the one you posted to dilan silva a aplir 27 2010.
++ some HT1632c led driver.
++ some pic16f628a, resistors, cable, etc.
++ a cold solder i constructed from a graphite an pc power soupply.
+++ and time, intentions to learn and basic English skills to access the world of tec.
By: Roberto Ocampo on February 15, 2011
at 12:42 pm
I have made the 16×24 matrix with 3.2v @20mA green leds. all the cathodes goes to the right (horizontal) and the anodes goes vertical. I do not know how to control each row and column. I mean the electronic components that i have to use. I plan to use to start up to get knowledge the
PIC16F628a (i have a couple of them)
the HT1632c from holtek (I have four of them).
I also have an other matrix 8×8 (same leds i builded for testing basics).
Any website you recommend to control the 8×8 matrix. that can show circuit diagrams_? to lear basic concepts.
I also have many. transistor PNP and NPN the 2907 and the 2222 respectively.
By: Roberto Ocampo on February 17, 2011
at 8:14 am
Hi Pasan,
Really glad and great to see how you have mastered LED displays with PIC 16F series. Normally commercial ones are using more advanced processors. Great work.
I live in Kottawa and I am a E. engineer. Would like to do something in electronics. But main constraint is the time coz I am working as an engineer and very limited time for development. Where do you get these big displays? Do you get it straight from a supplier or do you make it on your own?
Pasan, have you tried programming the PIC with JDM by USB to serial cable? Cos what I have now is a laptop with only USB, and my JDM does not work with it.
I hope to buy a PIC kit 3, but if there’s any other solution please let me know.
best regards,
Jathya
By: Jathya on March 16, 2011
at 10:55 am
” Normally commercial ones are using more advanced processors. ”
Yes, but you also can do lots of wonders even using 1Mhz speed.
” Would like to do something in electronics ”
What do you mean by that. Any how i never ever work under any one.
And I grow step by step not straigt to the top.
” But main constraint is the time coz I am working as an engineer ”
Yes agreed. And no I built these displays here.
And its damn time consuming. Soldering 6000 LEDs is really pain in the A#$.
Some time soldering those for longer hours makes me puke.
” Pasan, have you tried programming the PIC with JDM ”
yes JDM, if you are using JDM with your note book. You must have to give it a
external power supply. PIC needs 13V to flash it.
But your note book or your usb to rs232 converter cable does not supply that much volts.
Thats why it isn’t working. Do a google, you will find modified jdm schematics.
Or you just need single transistor.
” I hope to buy a PIC kit 3, but if there’s any other ”
If you are seriously in to PICs yes you better buy usb programmer.
JDMs programmers are always sucks. I think other hobby serious PIC lovers here
will also agree with me on this.
You also can build a PK2 for your self. Check this >> http://simon.derr.free.fr/site/spip/spip.php?article11
Thats just a one, there are tons of cloned Pk2s and Pk3s out there.
Also jathya, there are cloned PK2 s at pettha market. Locally assembled but working fine too. Will cost you like 2800 or 3000SLR
After all my PIC guru, Taught me well
Thank you Jathya for the comment.
Bye
By: pasanlaksiri on March 17, 2011
at 11:13 am
Hi Pasan,
Thanks a lot for taking your time to give elaborate comments, and making your home page as a learning place for beginners and enthusiasts from SL and from overseas. Together everyone can learn.
I never thought you would solder all those 6000 through hole LEDs by yourself! I think you can try finding surface mount LEDs so you don’t have to drill. But at the same time you have to drill for the jumpers. Also if you can find SMT LEDs pasted on a paper (like most capacitors come) it would make soldering easier.
” Would like to do something in electronics ” means would like to develop prototypes which are useful and marketable. Current interests are power protection, serial communication, data logging etc.
thanks for the comments regarding pic programmer.
By: Jathya on March 23, 2011
at 4:51 pm
Actually its 6144 LEDs. He he.
About SMT LEDs – yes agree. But it will not make any easy but it will
add some neatness. Also coz of SMTs there will be lots of through holes.
So after all it will be same as using normal ultra-high bright LEDs.
“ pasted on a paper “ – you know I am mostly targeting out-door displays.
Maintain the visibility at shining bright sun light conditions is really a big deal.
So would you think those Flexi Displays can generate that much contrast.
But how ever flexi display LEDs are much more powerful than our local market regular 2/= Rupee LEDs.
He he.
And the MOST IMPORTANT thing is maintain the END PRODCT COST.
You know Good quality SMT led will cost us like 20/=. So how about 6000 SMT leds sounds. He he.
“ Current interests are power protection, serial communication, data logging etc. “
Very interesting and I also love your interest.
I’ll also try to help you as I can.
Thank for commenting here Jathya.
Bye Bye..
By: pasanlaksiri on March 23, 2011
at 10:18 pm
hi Pasan,
went thru your website, impressive stuff.
i run a company and am looking for a good technician to repair some circuits maybe you can help me out.
let me know if you are interested.
By: dilshan on May 5, 2011
at 3:28 pm
Hi! Pasanla Nice works
By: Wasim on June 7, 2011
at 9:02 pm
Hi pasan
I am working computer hardware in university
I have been assembled 7×32 led dot matrix board using pic 16f84a and 4017 4 ics . But really not working. I using language is assembly. Can u help me fix errors that language
or using new language programming(mikro c).
But bullied 7×20 board is working (using 4017 2 ics)
Please send me above program to from (mickro c) 7×32 sing board.
thank you very much
chamila
By: chamila guanatialaka on June 8, 2011
at 4:29 pm
I have been massively helped by your swift email response, and am delighted by your follow up. I’m forever in your debt if I can be of assistance, I’ll hopefully show you a working something using it..
I literally copied the declarations, changed the port assignment, and within minutes I am no sat looking at a moving display.
Kindest thanks
Neal (Leics UK)
By: Neal (LeicesterUK) on June 18, 2011
at 6:33 am
hello sir, i’m sanath. and i’m student. your projects are great.
I wrote a program in CCSC for counting (B0 or B1 ) and PIC18F452. it is work well. Counting values will display In PC (Hyperterminal) .
But I want , When I pass values to PIC from PC (Ex : I send int “10″) , pic should be counted 1 to 10 and displayed “OK” .
Pleeeezzz give me some advices…………..
By: sanathkw on June 19, 2011
at 11:38 am
Sanath sounds like your a beginner. Im not sure what your actual problem is. Because you have said your able to send data via PICs uart.
So same as that send the max value that want to count up. And then tell the PIC to count up to that values.
Sanath when I type it here it sounds like easy. But when you actually going to do it u will probably face problems. But don’t back down it is the only way to learn.
Good Luck.
By: pasanlaksiri on June 19, 2011
at 11:47 pm
thanks lot of for consideration me …….
sir , I want to make a USB PIC programmer. I have a PCB and components. But I don’t have Hex file for pic on the programmer(PIC18F2xxx) .
sir , give me links or mail…………………
please………………………………
By: sanathkw on June 28, 2011
at 12:47 am
Go here and download the hex file
By: pasanlaksiri on June 28, 2011
at 7:03 am
Hi Pasan. I have a PIC16f88 ans would like to try your code.
Thanx
By: Mounir on July 12, 2011
at 10:59 pm
Hi! Pasan,
Nice to go through your web. I am interested in makin projects with led’s and matrix. Guess you could help me with some nice projects that you have in your belt. Keep the good job going.
Subroto
By: subroto ghosh on September 11, 2011
at 10:53 am
Hi! Pasan,
Nice to hear that your led matrix clock is ready and tested for all errors. I just watched the video of it am really interested in making it. The only thing is I have a huge number of 8×8 matrix modules and would like to make the display using them insted of the holtek display module. Do you have any suggestion on this. I am just waiting for you to upload the schematics and the hex files. Once again thanks for the information that you give out to your fans and the projects that you develop.
Regards
Subroto Ghosh
By: subroto ghosh on October 13, 2011
at 8:18 pm
How are you? I had a small issue looking at your website but regardless it’s a really awesome site
By: FredBlogs on November 20, 2011
at 3:57 pm
Hi, I am doing fine. Yes that issue may be because this blog hosted on wordpress. I will move it to unlimited bandwidth host provider.
Any how thank you very much for the comment.
By: pasanlaksiri on December 11, 2011
at 12:13 pm
Awesome Dude!
By: Hasantha on December 4, 2011
at 2:39 pm
Thank you Hasantha.
By: pasanlaksiri on December 11, 2011
at 12:14 pm
36*8 3coloure board 1k disigne karanna keeyak wenawada?
By: amila on March 1, 2012
at 4:51 pm
hi, I myself getting into micro contorller projects..with arduino. the hardware side is oky..! but i’m a complete noob to programming..! can u tell me where can i start to learn programming? is it hard to catchup.? by the way nice work.awsome projects.
By: Muhahmmedh Zaim (@mzee233) on March 12, 2012
at 8:46 am
Hi, When you getting in to some thing you have to start it from the scratch. First you do some hello world projects. Like blinking an LED.
Then study more about it. If you are using Arduino, there are tons of arduno play ground sites. You’ll be able to learn many new stuff if u dig deeper. Good Luck Zaim.
By: pasanlaksiri on March 12, 2012
at 5:25 pm
thanks mate..sure i will..!! and i’m following a C programming class..
to get things right from the beginning.. ! BTW i guess we went to the same college..! which batch r u..?
By: Muhahmmedh Zaim (@mzee233) on March 13, 2012
at 10:43 am
U went to DS ? Im 2004 AL.
By: pasanlaksiri on March 13, 2012
at 4:48 pm
yeah…i’m 2007 A/L…BTW nice to meet u brother.I add u in FB.
By: Muhahmmedh Zaim (@mzee233) on March 13, 2012
at 7:40 pm
Nice to meet you too Zaim.
By: pasanlaksiri on March 14, 2012
at 11:48 am
Pasan, It’s a pleasure to know one of our own Sri Lankans doing well in the field of electronis and ever prepared to impart knowledge with fellow beings.I came across this while pursuing joulie thief circuits on the web.Fantastic responses with good advice right throughout.Regrds-Spencer
By: spencer perera on May 24, 2012
at 9:14 pm