hi, i'm new to microcontroller program . i have 89c51 controller max 232 ic, but to program i need athor programmer, is any possiblety to built my own programmer. please help me,
Sorry for hijack, but I have asked before about this elusive $25 programming cable without getting any answer.
I see many references to that $25 cable, but have failed to locate it.
I have contacted Atmel support and they have failed to supply info about how to build one and they can't sell me one or point me to anyone who sells them. Instead, they recommend that I invert the reset signal and uses a STK500 starter kit as adapter.
Once upon a time, there has been a document on the Atmel site with the description of this elusive cable. I can still find many posts mentioning this description and specifying the - now defunct - link.
Anyone who can help out?
" href= "http://www.electronicsforu.com/electronicsforu/lab/ad.asp?url=/EFYLinux/circuit/feb2005/Circ05-Feb05.pdf&title=Atmel%20AVR%20ISP%20Dongle"> www.electronicsforu.com/.../ad.asp
Oh, and if you google "atmel isp cable" the second result is the document you wanted from the atmel site.
www.atmel.com/.../doc3310.pdf
There seems to have once been a description of this cable, i.e. how it was connected. The related link is just the pinout of the ISP side - not the corresponding parallel port pins.
There are links to be found on the net, but the document seems to have been pulled from the Atmel site.
I did contact Atmel support for the nordic countries last year about it, since I then was in very big need of a cable in a hurry. They could not produce the document or a supplier in Sweden. But their suggested workaround was to invert the reset signal and use a AVR SDK500 kit.
If I need to program more AT89S chips, I should probably get a AT89ISP cable, since it is a bit more compact than the big SDK500 board. On the other hand, the machine I'm writing this on may probably be the last machine I'll have with a parallel port.
It seems likely that the DIY schematics is more or less identical to the official AT89ISP cable since the only signaling difference is the inversion of the reset - something the PC program can directly handle.