ISP programming of AVR

[Guest]

Hello!
I'm struggling to program a ATmega88 soldered to a prototype board I made. Supply voltage is 5V.
The board is laid out with a connector similar to the one on the programmer, and I am using the supplied ISP cable.
I have nothing connected to the ISP lines except for a 100k pullup on the reset line, as recommended in the Dataman Help.

I have successfully programmed the device a few times, both the program itself (flash) and the fuses. This was, however, not consistent and reliable. Sometimes I had to inject a 1MHz clock signal on XTAL1.

I have noticed when the ISP cable is connected, the reset line is at 2V. That doesn't seem right. The reset line is close to 5V when the ISP cable is not connected.

The ATmega88 seems to be working, with a 8MHz clock signal present on the CLKOUT pin and a PWM signal from the OCR1A output.

I have used the STK500 for ISP programming AVRs on many occasions, never a hitch. Just thought I'd mention it.

Any idea, anyone?
Or should I just get an AVRISP?

Thomass

[Dataman (Neil Parker)]

Hello Thomass,

Which programmer are you using? If you can recreate the failure during programming then use the HELP menu "Create problem report" feature which will place a text file log on your desktop, if you could email this to me at neil@dataman.com then I can start investigating the problem.

Regards,

Neil