Sony Vaio low voltage

[Fu manchu]

hi there all,

i built a pic programmer which is featured on this website:

**broken link removed**

it works fine on my pc but when i got a new laptop i found that the the voltage output on the RS232 port is +/- 5v and with a load on it can be as low as +/-2.5v how can this be, this is lower than the +/-3v error region?

So for a while now i have been trying many different way to solve this problem but i have run out of ideas!

the basic idea is to build a circuit that will amplify the voltage, but it has to be bi directional and i am not sure with pins in the circuit, on the above website, to use.

is there anybody out there that can help

 

[Nigel Goodwin]

hi there all,

i built a pic programmer which is featured on this website:

**broken link removed**

it works fine on my pc but when i got a new laptop i found that the the voltage output on the RS232 port is +/- 5v and with a load on it can be as low as +/-2.5v how can this be, this is lower than the +/-3v error region?

This is a common problem with the crude programmers which use a serial port in a non-standard way.

Does your laptop have a parallel port?, if so you could use a standard parallel port programmer.

If not, you could use a USB programmer, DIY Electronics sell a cheap and simple USB/Serial kit - you could connect this to either your USB or serial port.

 

[Fu manchu]

Parallel Port programming

Okay i have given up on trying to program my pic using the serial port, so nigel or any one else out there, do you have a simple circuit i could try out to make sure its compatable with my computer?

 

[bmcculla]

You could also buy a USB to Serial converter and use your serial programmer from that. They only cost a couple buck these days. Hopefully the output voltages will be closer to RS232 spec.

Brent

 

[Fu manchu]

Already tried using a usb to serial convertor it was one of the first things i tried but this was with both winpic and icprog but still problems, infact i get more problems, the verify and read throw up zeros instead of the usual 3FFF.

i have decided to build the AN589 parrallel programmer and see if this works :?:

This is the PDF:

**broken link removed**

and also i have found a circuit for the serial port which looks promising

**broken link removed**
serpic interface

This circuit looks like it amplifies the voltage of the serial port hence the original problem?

I think i shall try both and see what happens :!:

 

[Nigel Goodwin]

Already tried using a usb to serial convertor it was one of the first things i tried but this was with both winpic and icprog but still problems, infact i get more problems, the verify and read throw up zeros instead of the usual 3FFF.

Well those programmers don't actually use the serial port as such, they simply toggle the handshake lines, so a USB converter isn't liable to work. Although I have heard from one person who managed to do so, but I don't know what he was using.

i have decided to build the AN589 parrallel programmer and see if this works :?:

This is the PDF:

**broken link removed**

I wouldn't advise the AN589 programmer, it's an obscure design which MicroChip came up with. I would recommend a 'David Tait' (the father of PIC programmers) style parallel port programmer. One of the most popular is the P16PRO40, which will accept PIC's from 8-40 pins. There's also the P16PRO for 18 pin only. Most software will support these programmers, the AN589 is pretty well limited to the software that MicroChip provide in the PDF.

You can download the circuit for the P16PRO40 from various places, including my website at http://www.winpicprog.co.uk.