I'm using an Arduino UNO to program a pre-compiled hex image to an ATTINY45, using the avrdude in the Arduino IDE directory, on Windows 7. The Uno has the ISP sketch loaded from the examples directory and that works- the heartbeat LED pulses nicely.
On the hardware side I have this setup, except the ATTINY is surface-mount, soldered to a surfboard with all its pins verified-soldered with a voltmeter. I use a header-pin strip, held by hand to get the pins touching the surfboard, to get the signals from the Uno to the ATTINY.
Here are the command lines, which I took from looking at the IDE's debugging output:
REM set the fuse for 8MHz, so the ISP programmer can work C:\Progra~1\Arduino\hardware\tools\avr\bin\avrdude -CC:\Progra~1\Arduino\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -pattiny45 -cstk500v1 -P\\.\COM7 -b19200 -e -Uefuse:w:0xff:m -Uhfuse:w:0xdf:m -Ulfuse:w:0xe2:m REM load the program C:\Progra~1\Arduino\hardware\tools\avr\bin\avrdude -CC:\Progra~1\Arduino\hardware/tools/avr/etc/avrdude.conf -v -pattiny45 -cstk500v1 -P\\.\COM7 -b19200 -Uflash:w:firefly.hex:i REM set fuse for 1MHz, as the project requires C:\Progra~1\Arduino\hardware/tools/avr/bin/avrdude -CC:\Progra~1\Arduino\hardware/tools/avr/etc/avrdude.conf -v -pattiny45 -cstk500v1 -P\\.\COM7 -b19200 -e -Uefuse:w:0xff:m -Uhfuse:w:0xdf:m -Ulfuse:w:0x62:m
-I try running those separately, but always get this error:
avrdude: Device signature = 0x000000 avrdude: Yikes! Invalid device signature. Double check connections and try again, or use -F to override this check.
but sometimes the number is ff0000 or ffff00 or ffffff
I read that "Arduino uses a slightly modified version of avrdude to upload sketches to the Arduino board. The standard version queries for the board's device signature in a way not understood by the bootloader, resulting in this error." Does this mean that using the Arduino avrdude with a new ATTINY chip, no bootloader on it, would also cause that same error? In other words, is the modified avrdude incapable of querying a non-Arduino-bootloaded AVR chip?
Or does that error simply mean I don't have a good contact between all my programmer pins and the ATTINY?
And, are the fuse settings truly needed, can the Uno program the flash into an attiny running at 1MHz and thus save me some steps?
(I would just buy a "real" programmer, but need to get this code in the next two days, and am in a rural part of Nova Scotia)