A breath of life, i hope.

[1mmort41]

 
OK here goes. i have an old LED project i made in my school days and its been beaten up pretty bad. its LED's are missing and the buttons gone but i hope it can still be used.

there it is. i have some spare cable and a female serial com port. got the wiring specs from
http://www.instructables.com/id/PicAxe-Serial-Download-Cable-homemade-from-scrap/
so i was wondering... if i wire this up properly will i still be able to program my chip with my bashed up old project. and if the board will work, can i use a usb-serial adapter to make my device usb programmable?
just wondering because i thought if some of you tech guys out there could splice up the circuit Ive made to just the program side with no LED's or switch, you could post it here and well all be able to get an extremely cheap 8 pin chip programmer. that works via usb... as Ive gathered theres a very high demand for these so i hope i can help!
also the pic used when this was originally made is the 12f629 if that makes any difference... I'm new so any information regarding this post is a bonus to me. Thanks for any help 

[802Chives]

hey Immort, the reason a pic axe can be programmed with just a serial cable is because a pic axe is a chip with a bootloader program pre installed on it. A bootloader is a program that can accept a new set of instructions via a serial cable or usb, and write to its own memory space.  Just a  blank standard pic requires you use a programmer in order to load any sort of code, and not all pics can write to their own memory.

Serial is the typical protocol that is used to load your code to the bootloader.  Usb is looking like a very attractive upgrade to the serial method, however it completely changes the communications software on your chip and on your pc.  long story short usb is not a simple hardware fix and the serial cable you linked is for pic axe which is different then a blank pic because when you buy a pic axe you are paying for the bootloader pre-installed on it so you can use there simplified software to write a code.


I like your circuit tho, looks like it makes use of "charlie-plexing" to operate you LEDs.

[1mmort41]

yeh the pic i have on it is a picaxe... sorry i didnt mention it before. but are you saying that this needs to have the serial cable only? because i was thinking of buying a usb-serial adapter on ebay and using that, or is it not possible to program a picaxe chip in this way?

[802Chives]

I am not sure about the usb to serial, I suspect someone has gotten to work, but most everyone here doesnt use pic axe rather just a standard pic.  you should check out a picaxe forum before you purchase anything.

You should be able to program a pic axe using just a serial cable and their software.  I have seen people use headphone jacks for programming the picaxe as it only needs 3 wires to be programmed vs the 5 that are used for normal pic programming.