7c80 install on rpi 4

I would verify that you have sufficient differential voltage
(preferable >2V) across the A,/A B,/B and Z,/Z pairs
and that the differential voltage changes polarity
when you move the spindle shaft to different positions

i read -4,2 to + 4,2 volt
I will do tests with the signal of my servo motor amp this week.

Hi everybody,
I got a new 7c80 and to play around with it I installed three Nema 23 Steppers with DM542 amplifiers. I followed this thread and installed linuxcnc 2.9 on a SD 64 bit for the pi and compiled mesaflash.
The 7c80 is powered and supplies the pi with energy over the 40 pin ribbon.
I copied the 7c80 bitfiles in the mesaflash directory and tried to flash the 7c80d.bit on the 7c80 with

mesaflash --device 7c80 --addr /dev/spidev0.0 --spi --write 7c80d.bit

I get:

open: no such file or directory
No 7c80 board found

under /dev there is no spidev0.0 device.
I'm stuck.
Help would be appreciated.

The 7C80 already has installed firmware (7c80d.bit) so unless you need to
support a specific daughtercard, I would leave in installed firmware alone,
especially when you are not certain of the interface reliability.

AFAIK you need to specifically enable SPI with raspi-config

A safe mesaflash command to test the interface would be:

mesaflash --device 7c80 --addr /dev/spidev0.0 --spi --readhmid

One step forward, after enabling SPI I do a
mesaflash --device 7c80 --addr /dev/spidev0.0 --spi --readhmid
and I get
unable to set bpw32, fallback to bpw8
Unexpected cookie at 0100..0110:
00000000 00000000 00000000
No 7C80 board found

1. Did the 7C80 successfully self configure at power up? (no red lights on after power up)
2. Are you using a short 40 pin cable (no longer than ~2 inches,~50 mm) ?