uJDM Modification, need help!!!

[amady]

I was built uJDM programmer and it won't work because my desktop serial supply is +8.3V only, not enough on burning process. So i get an idea to boost up the voltage by given a supply +12V or +6V (depend on serial voltage). I not try yet, just i want to share and get some idea or suggestion from all electro-tech-online friend... :lol: Here i attach the modification cct...

 

[Nigel Goodwin]

At that you're feeding the 12V directly into the Txd pin of the serial port, which is probably going to blow it!.

If you search the net for 'jdm programmer' you will find plenty of sites with the JDM programmer modified for an external supply.

 

[amady]

Voltage regulator

Nigel: if i put voltage regulator to boost the TxD voltage can or not?

 

[amady]

At that you're feeding the 12V directly into the Txd pin of the serial port, which is probably going to blow it!.

If you search the net for 'jdm programmer' you will find plenty of sites with the JDM programmer modified for an external supply.

Nigel: If my serial port just reading 8.3V, so i can't built up for RCD programmer (cct shows below)...that true??

 

[Nigel Goodwin]

As I've mentioned before, these simple 'serial port' programmers are very critical with regard to the port they connect to. If you really have to use a serial port, I would strongly advise you to spend a little more money and buy a kit for a proper serial port programmer with an on-board processor.

You might like to look at this one, which is both serial and USB https://www.dontronics.com/diyk149.html.

 

[amady]

As I've mentioned before, these simple 'serial port' programmers are very critical with regard to the port they connect to. If you really have to use a serial port, I would strongly advise you to spend a little more money and buy a kit for a proper serial port programmer with an on-board processor.

You might like to look at this one, which is both serial and USB https://www.dontronics.com/diyk149.html.

Nigel: So, you have any suggestion if i want to using parallel port or you has schematic diagram (easy to learn) for PIC16F84A ( i only has this IC)

TQ

 

[Nigel Goodwin]

Nigel: So, you have any suggestion if i want to using parallel port or you has schematic diagram (easy to learn) for PIC16F84A ( i only has this IC)

The P16PRO40, you can buy it cheaply as a kit, or you can download the circuit from various places, including my own site. It works with either WinPicProg or IC-Prog, both of which are free.

 

[Barry]

Hello amady,
When I started out with PICs, my very first programmer was a JDM variant from Talking Electronics. They use a very clever method of using diodes and zeners in the circuit to make use of +8V and -8V to give you 16V via the serial port. I have never had any problems with this programmer and I use it on my Dell laptop when not at home. At home I have a P16Pro setup on a PC with a seperate power supply.
If you are interested, you can have a look at http://www.talkingelectronics.com - find the multichip programmer and have a look at the article which also includes the schematic of the programmer. They also have a lot of other very interesting goodies for PIC related projects.
Hope this info is of use to you.
Barry.
PS. Scroll down left side and find Multi Chip Programmer.

 

[amady]

Nigel: So, you have any suggestion if i want to using parallel port or you has schematic diagram (easy to learn) for PIC16F84A ( i only has this IC)

The P16PRO40, you can buy it cheaply as a kit, or you can download the circuit from various places, including my own site. It works with either WinPicProg or IC-Prog, both of which are free.

Thank nigel for your advice... actually my RCD programmer was work but only with winpic software (icprog--failed)... I was found that my serial port is not enabled on bios program...