USB based PIC 16F84 programmer

Thread Starter

Usama_ali143

Joined Jul 17, 2017
27
Hi guys! I want to Build a cheap PIC 16F84 programmer that can be connect with my LAPTOP. but LAPTOP does not have serial COM port. how can i accomplish this? guide me plz..Thankx
 

LesJones

Joined Jan 8, 2017
2,696
If you can use a PIC16f84A instead of a PIC16F84 then you could build a clone PICKIT2. You should find designs on the web for a clone PICKIT2. It MAY work with the PIC16F84 but is is not shown as supported in the PICKT2 software.

Les.
 

be80be

Joined Jul 5, 2008
2,049
You can program it with the pickit2 just use the manul setting and set to the 16f84a there just little changes from the 16f84 to the 16f84a but I've used both with a pickit2
 

Thread Starter

Usama_ali143

Joined Jul 17, 2017
27
pic16f84-16f84a-16c84-16f628-programmer-circuit.jpg 10196119.jpg
I have bought a USB to DB9 adopter cable and i m going to implement the attached circuit for PIC 16F84 programmer. will it work with laptop directly? any comments please
 

be80be

Joined Jul 5, 2008
2,049
Nope it will not work you need 12 to 13 volts on the mclr pin you can see but most of them
USB to DB9 adopter cable only go to 6 volt max.
What you could do is get a 12 volt wall wart and add 2 transistors on pin 4 to bring mclr to programming voltage.
 

JohnInTX

Joined Jun 26, 2012
4,281
I have my doubts. The programmer is described here:
http://www.electronicecircuits.com/electronic-circuits/pic-programmer#more-707
Connect the PIC programmer to 1st or 2nd COM PORT of computer by using RS232 wire.
It uses a driver (WinXP is the latest one given) which wiggles the resident COM port pins directly to make the clock/data ICSP signals to program the F84A. Adding a USB -> COM port adapter adds some layers between that and the USB driver may bypass the resident drivers completely. That could cause it not to perform the required bit timings or not work at all.

Give it a try but don't invest a lot of time in it. Consider upgrading your project to a PIC from this century using a $16 Curiosity board.
http://www.microchip.com/developmenttools/ProductDetails.aspx?PartNO=DM164137
A PIC16F1826 is a pin compatible replacement for the F84A and costs about 1/3 as much. The Curiosity boards have a full programmer AND debugger (like a PICkit) on board. Add MPLABX and a USB cable and you are ready to go. Assembly code for the F84A ports relatively easy to the '1826 (I just did a couple). C is even easier.

And I don't mean to seem overly pessimistic, I've just seen lots of clone stuff and hacked IO port stuff and old PIC stuff sold that really isn't very good if it works at all.

Give it some thought.
 
Last edited:

be80be

Joined Jul 5, 2008
2,049
It's hard to use a jdm programmer without a real serial com port and to find a real comport you got use a really old computer lot's of them never come close to the volts needed to put the chip in program.

I wouldn't even waste my time with a pickit2 these newer chips are great like PIC16F1826 as been said
the PIC16F1825 the PIC16F18855 there cheap and love C programming or ASM but C is so easy with the mplab-x and MMC to setup a chip.

Just wish I was better at C can't get the hang of && || ++ but I'm getting there.
I've had good luck with the pickit3 after I started powering the chips. Even a cheap clone works good.
$11.00 bucks It works just as good as a real one.
 
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