stk500 ISP programming on external pcb?

Go To Last Post
6 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I was wondering if it was possible to program a avr which isn't mounted in the stk500 board, but using the stk500 isp header. I tried breadboarding an atmega8515 (with a 3.68Mhz crystal), and connecting the isp wires to the atmega8515 pins, but AVR Studio won't program it.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Quote:

I was wondering if it was possible to program a avr which isn't mounted in the stk500 board, but using the stk500 isp header.

Yes, I've done it every day, many times, for years. All of our production boards have ISP headers, and almost all are programmed with STK500 or equivalent ATAVRISP/ATAVRISP2.

Just because you attached a crystal doesn't mean that the AVR is looking for it as a clock source. Is the crystal attached properly with the right value load caps? Is it oscillating? Reset circuit? Power and ground? Attached circuitry on the ISP pins? Etc. etc.

I'll have to see if I can dig out one of many "ISP failure" threads & checklists. We all could save a lot of typing if it were sticky.

Lee

https://www.avrfreaks.net/index.p...
https://www.avrfreaks.net/index.p...
https://www.avrfreaks.net/index.p...
https://www.avrfreaks.net/index.p...

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thanks for the quick reply. I have the crystal connected between xtal1 and xtal2, have 22pF caps to ground from xtal1 and xtal2. I have the fuse bits set to use the external crystal. And the STK500 is set to program the ISP at 4khz. I'm using the ISP header to supply +5v and gnd to the chip. There is no other circuitry on the sck/miso/mosi lines.

Last Edited: Tue. May 8, 2007 - 11:54 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

mooseydoom wrote:
I'm using the ISP header to supply +5v and gnd to the chip.

I don't have an STK500, but with the AVRISP, it's the other way around. The target board is suppose to supply the power.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

My multimeter shows that the vtg pin from the isp header is powered to +5V from the stk board

I've also tried using an external power supply for the chip, connecting the grounds of the external power supply to the stk ground (but not connecting the +5v), but it doesn't work either.

My connections:
ISP gnd => gnd (pin 20)
ISP vtg => vcc (pin 40)
ISP mosi => mosi/pb5 (pin6)
ISP miso => miso/pb6 (pin7)
ISP sck => sck/pb7 (pin8)
ISP rst => reset (pin9)

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I think somehow the lock bit got set on the 8515 chip, disabling programming. =\ Put the chip back in the STK board and fixed it. Thanks for the help