Yet another PIC programmer problem, PIC 16F628A

[manu_alld]

i built this PIC programmer to write a small file to 16F628A
http://www.semis.demon.co.uk/uJDM/uJDMmain.htm

the hex file is correct and is not having code errors.

using desktop (OS VISTA SP2) connected it and it gets detected, L.E.D. is lit
its able to read the PIC, erase PIC's but it doesn't write to it.

I measured voltage across many pins and its 12+ where it should be, so its certainly not a com port on newer hardware not giving the proper voltage.

tried using win7 64 bit edition it fails there too.

I used IC-prog, winpic800 but all fail writing to PIC.
with same error

can some shed some light.

I also read "http://feng3.cool.ne.jp/en/rcd.html"
which suggests using a "470uF" if you make a RCD programmer,
I am now trying to use this capacitor value on ujdm programmer and see if it works.

can someone suggest any programmer which works with 16F628A and is easy and cheaper to make.

Thanks for your attention.
manu

[manu_alld]

Google is a true friend indeed cause i think i wrongly connected BC547B as "CBE" while the one i was using had "EBC" pins.

Swapped it and tried to burn the PIC 16f628A and same error.
then i tried with another PIC 16f628A, and wow, it got programmed and
got verified with no errors. I used IC-prog with the simple uJDM programmer.

i think i smoked one PIC cause it was always giving error it was the one which i erased 100 times and tried again and again but as the transistor polarity was reversed it may have got smoked.

I'll test the programmed PIC 16f628A in my project tonight and post the results to let everyone know.

thanks for watching this thread.

[Ian VK3XID]

Have a look at the comment by Ken Ho in the following web site for a similar problem, a floating pin may be inhibiting the write operation.

http://www.electro-tech-online.com/microcontrollers/23735-programming-pic16f628a-using-pickit2.html
Ian VK3XID

[mvs sarma]

in fact the zif socket has gnd at its pin number 22
which becomes pin10 for 18 pin pics and it is exactly RB4 (PGM) pin.
so any user using a zif socket may not have issues. If some one extends the icsp wires and tries to program perhaps (s)he needs to ground pin 10 of 16F628A for effective programming. I only hope manu_alld has a zif socket.
_________________
Regards
Sarma

[ZS4JAN]

Hello Manu

I,ve also tried JDM programmers for the 16F628 and no luck. I like the JDM programmers because I use mostly 16F84's for my projects, and you don't need external power supplies.

Here is a programmer that worke everytime with the 16F628. It is the TAIT programmer with a parallel port and 7407 + PNP transistor driver, and makes use of external power supply.

Unfortunately I no not have the diagram with me, because at the time of building the TAIT programmer, I was using the internet circuit. I am sure that Google will take you to the TAIT programmer.

I am using WINPIC software and the following settings is important:

1. Tait, 7407(driver) + PNP transistor (interface type)
2. In I/O Port Access Driver select SMPort

I want to try and change the JDM programmer to use an external power supply. I believe that will sort this problem.

[mvs sarma]

[ZS4JAN]

Hello Sarma

I see you are also using the TAIT programmer. Mine is connected to the LPT(parallel) port. You mentioned the COM port.

Is this correct ?

I'd like to change the TAIT programmer to work with a standard COM (serial db9) port. I know that the my WINPIC software will not support this change.

Is there a serial programmer with external power supply that will work with WINPIC ?
_________________
Regards
Jan...ZS4JAN

[mvs sarma]

Tait programmer always worked on DB25 socket and what i referred to is a comport based programmer designed by DL4YHF. it is a simple one and I made pcb with icsp connector as output, instead of the ZIF socket.
_________________
Regards
Sarma

[ZS4JAN]

I've build myself a serial programmer with external power supply. This work excellent. I've tested it with most of the 12Cxx, 16F84xx, 16F628xx, 16F876xx, 16F877xx series PIC's.

The programmer programs first time with no problems. I am using WINPIC. The programmer will work under JDM or COM84.

The VPP line is switched for 12.7V. I am supplying the programmer with 13.8V from my bench supply. Even turning the bench supply down to 12V, the programmer is programming first time, everytime. No more little jumpers for the 16F628 or rise time problems with the 16F876A. Just select your PIC in WINPIC software and hit the program button.

The basic diagram can be founded in WINPIC.
Click on "Help on COM84"
There is two diagrams to be seen. I've used the last interface diagram and modified that one. All the different PIC sockets is now available on my programmer.

I've tested this programmer also with my USB/SERIAL converter. It programs first time as in the case of the serial port. My laptop that I use for PIC programming has COM, LPT and USB ports. I've decided on the serial (COM) programmer because computers with LPT ports are phased out. Serial ports are also quickly on the phase out, and therefore my test on USB.

At least I am sorted for the future with regards to communication ports and PIC programmers.

The pc template was created today with ARES and I will sent it tommorrow for manufacturing.
_________________
Regards
Jan...ZS4JAN

[mvs sarma]

It is Nice to notice that you have a nicely working programmer.

Let us try to encourage the USB based Pickit2 or pickit2 or corresponding clones. Let us see the world trend that most Laptops and note books would no longer have COM or Parallel ports.

I also came to know that some desktop motherboards even dont have parallel and com ports.

Thanks for your offer and for some time to come it would be useful

By the way, I hope that you have seen FENG programmer that is working well. Yesterday I am told by a local person (Mr Ansari) that if we have 10K resistor from Vcc to MCLR, the issue of reading 0000 error did not come for him
Thanks Mr Ansari.
_________________
Regards
Sarma

[manu_alld]

mvs sarma sir and "ZS4JAN" I am finally able to program 16F628A using JDM programmer, the same one i linked in 1st post.

No external power supply.
Using com port on m desktop with Intel 41RQ motherboard for core2duo.
OS vista.
I was able to program using winpic and ic-prog.

Although using a USB based programmer would go a long way and one could use latest laptops etc, take their project along with no worry of re-programming on remote locations but I think making yoru own USB pic kit is complex currently.

MVS sir, i was not able to find a ZIF socket in my town, using a temporary solution with 18pin DIP Socket.

Lastly I need 16F628A but its expensive at one online store and ebay seller from china would ship atleast 10 pcs for 20usd which comes to Rs.95-Rs.100 each which looks good.

If anyone can help me get 16f628A in India at reasonable price i would be greatful.

Thanks for yoru time.

[manu_alld]

just to update i found a online store from India which sells PIC and i got a few @Rs.80/each.

It should reach me in a week.
I'll post the details then.

[mvs sarma]

[manu_alld]