Arduino as ISP question

Sorry for the noob questions- I did search using every combination of keywords I could think of without success. :frowning:
I can program my atTiny85 just fine using my Arduino nano programmed with the ISP sketch…

BUT - I have to do the “Upload using Programmer” from the dropdown menu TWICE each time to get it to program my chip - the first time through always throws a error message (See last few lines of this error message - copied in full as attachment in case that might be helpful):

Interestingly enough, if I DON’T cycle the power to the Arduino, (i.e., if I just burn the sketch to the atTiny I just programmed after it finishes programming on the second time around), it programs the atTiny the first time around without any problems.

Am I doing something wrong, or is this just a bug in the Arduino as ISP software?

And can I use the Arduino nano programmed as ISP with avrDude to set fuses? There is a nice site that has an online tool for setting fuses, and I’m wondering if the Arduino will appear to the USB port and Atmel Studio as the plain old AVRISP mkII programmer, or if it is not really compatible outside the Arduino Development Environment?

error message.txt (20.9 KB)

How did you disable auto-reset?

How did you disable auto-reset?

I don't understand your question.

The RESET pin on the atTiny is connected directly to the D13 pin on the nano. The RST pin on the nano isn't connected to anything.

The other connections to the atTiny are from pins D10, D11, and D12 on the nano.

Both atTiny and nano are powered from the USB port on the host PC. The port is powering both the atTiny and the nano for many seconds before I click on "Upload using Programmer" from the Arduino dropdown menu, so both should have had plenty of time to come out of RESET from power-up. And it does program correctly the second time though very consistently. Seems weird. :o

Do I understand from your question that there is something missing in the RESET connections?

mrcoffee: The RST pin on the nano isn't connected to anything.

Then there's you're problem. ;) When using a Arduino as ISP you want the ArduinoISP to just run. But normally the PC resets the PC when opening the serial port. To stop that from happening you need a +-10uF capacitor between the RST and GND.

Thanks - that 10 uf capacitor fixed it!

And my second question

And can I use the Arduino nano programmed as ISP with avrDude to set fuses? There is a nice site that has an online tool for setting fuses, and I'm wondering if the Arduino will appear to the USB port and Atmel Studio as the plain old AVRISP mkII programmer, or if it is not really compatible outside the Arduino Development Environment?

mr coffee

You can use it with avrdude from the command line. Don’t know on Atmel studio.