intermittent connection with LIS3DH accelerometer

[jim546]

I've connected an LIS3DH to a duet Maestro running RepRapFirmware for Duet 2 Maestro version 3.3 (2021-06-15 21:47:01). When M955 P0 C"twd0+twck0" is sent about a quarter of the time it responds: Error: M955: Accelerometer not found on specified port.
Most of the time it sends:
M955 P0 C"twd0+twck0"
Accelerometer 0 with orientation 20 samples at 1344Hz with 10-bit resolution
After the accelerometer is connected, about half the time when an m956 command is run the printer soft resets.
I checked the wiring for the int pin with a multi meter to verify it was connected to the proper location and had a stable connection.
The wire is about 2.5 meters of cat 6 connected with DuPont connectors.
m122.txt

[gloomyandy]

@jim546 2.5m is relatively long for an SPI connection. You may have more luck using a USB3 cable with the various pairs wired as described here: https://forum.duet3d.com/topic/22878/software-package-3-3beta3-released/68?_=1624809172098 a number of people have reported things working with longish cable runs and this sort of connection.

[dc42]

@jim546 said in intermittent connection with LIS3DH accelerometer:

After the accelerometer is connected, about half the time when an m956 command is run the printer soft resets.

That's not normal. Please provide a M122 report taken after the printer resets.

[jim546]

@dc42 m122 2.txt

[jim546]

I re wired the connector using the twisted pairs as if I was using a usb3 cable and it seems to be working so far.
I probably should document that the the first half of the cable is cat 6a and the second half is cat 7.
Thanks for the help.