Problems with pic programmer

[AcmeMan]

Hi
i build a jdm, with an indipendent power supply, to program PIC. As interface i've used a DB9 serial port but i've got some problems with my USB - DB9 serial convertor. In fact my programmer work fine with the serial port of an old PC but it won't work with a USB-Serial converter (my main PC has only usb port). I've done some research over internet and more people seem to have the same problem with this kind hardware, could u give me a more information about that? Is there a programmer that works fine using a usb-serial convertor?

 

[Shax]

I've also had problems using a JDM programmer and a USB - Serial converter.

I now use a PicKit2 programmer, and a couple of ZIF adapter boards that I built. It works fine for all the PIC micros I use.

clicky clicky the link for more info :

https://www.microchipdirect.com/productsearch.aspx?Keywords=DV164120

 

[AcmeMan]

I'd like to build the programmer by myself. Could u post the scheme?

 

[AcmeMan]

I've read over internet that Velleman programmer works fine with the usb-serial convert, is there someone that could confirm that?

 

[Nigel Goodwin]

The only way to be sure is to use a real serial port programmer, like the InchWorm - you NEED a processor on board for a serial port programmer. JDM style programmers, that connect to the serial port (but don't use it) simply waggle the handshake lines - this doesn't transfer well through most USB/Serial converters.

 

[AcmeMan]

InchWorm? Could u give me a link?

 

[Nigel Goodwin]

Just search in this forum!.

 

[DeeJay]

I've read over internet that Velleman programmer works fine with the usb-serial convert, is there someone that could confirm that?

On the contrary, if you read Velleman's own product pages and forums for their K8048 and K8076 PIC programmer devices you will see that they explictly state that usb-serial convertors are not supported and that a real serial port is required.

 

[AcmeMan]

I've just found this document:
https://www.electro-tech-online.com/attachments/inchworm-assembly-instructions-pdf.9431/
it seems that the difference between classical jdc, or other programmer it's just the max232 that normalize the voltage level. So could i just add a max232 to my jdm programmer to obtain a result?

 

[taner]

I use a parallel port (LPT) programmer P16PRO,
its work very reliable

 

[akg]

the jdm requires the higher level voltages from an rs232 , hence it may not work with laptops and usb adapters

 

[evandude]

I think it's safe to say that if you don't have a real serial port (ie - a desktop serial port, not a laptop or a usb-serial adapter), you might as well forget about using a JDM. You might be able to find the some way to make it work with some "band-aid" circuitry, etc, but you're pretty much guaranteed to endure a lot of headaches in the process, and probably still won't end up with a reliable programmer in the end.

There are other options out there, ie - parallel programmers, PROPER serial programmers (that don't draw power from or otherwise abuse the serial port), and USB programmers... JDM serial programmers are almost invariably the cheapest option, but they're still a waste of time and money if they simply won't work for you because of your computer hardware, so you might as well look into more suitable options, even if it costs slightly more.

 

[AcmeMan]

I use a parallel port (LPT) programmer P16PRO,
its work very reliable

My programmer it's like your but i have used the serial port instead of parallel. I think that i'll try the way of max232 and at least i use the parallel port.