Having some trouble with getting 0x04 responce on the 0x04 reset command.
I'm doing the HW reset as described. The signals from raspi passed through level shifters.
Chip select DI CLK are ok. I see 0x04 passing into the chip but there is nothing at the output.
The VDDcore is 0.7 volts. Maybe it is too low?
That's pretty likely too low. I had similar issues when I was running the chip that low. 0.8V seems to be pretty reliable for at least basic comms for most chips. A couple wouldn't hash at that voltage but once I brought it up to about 0.84V they were fine.
Of course, now those chips run hotter than the others

I know it is an old topic but I have a question. I am working on the firmware for the A2's, which are pretty much the same as the A1's. However, it seems to be possible to adjust the VDD_Core voltage by software. How did you guys change the VDD_CORE voltage???
Greatly appriciated,
emdje
That depends on your board layout and voltage regulators. If you've got an A2 terminator I'd be quite interested in trying to reverse engineer this. Otherwise we likely need at least the schematics of the board.