avrdude unable to write hex to attiny45

Question

I'm using mac/avrcrosspack.

this should write hexfile to the chip:

avrdude -c avrisp -p t45 -P /dev/tty.usbmodem411 -e -b 19200  –U flash:w:gp2.hex:i

but it only reads the contents of the chip and happily ends:

avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.05s
avrdude: Device signature = 0x1e9206
avrdude: erasing chip
avrdude: safemode: Fuses OK (H:FF, E:DF, L:E2)
avrdude done.  Thank you.

even if I change the filename to something which doesn't exist in the folder, it does the same. it looks like it can't find the file so it just quits without error. How can I specify the whole path in the flash:w: argument or where should I put the hex so it works?

Answer 1

but it only reads the contents of the chip and happily ends:

I don't see where it "reads the contents", but it seems to only erase the chip and doesn't perform the flashing afterwards.

avrdude: erasing chip

Looking at your command line, the -e (erase) parameter may override the following flash option. As far as i know, if you flash a device, the erase is performed implicitly.

Try removing the -e option.