SAMD SERCOM number for Duet2 w Duex

General Discussion
1

Hi,
Trying to connect a thermocouple daughter board - Duet3d’s 2x Max 31856 board - to the SPI header on the duet2 wifi - I know i have to define a SAMD sercom but I can’t seem to find what the sercom number is for these pins (SPI0.CS1-4). Would also like to get my adxl345 accelerometer connected through these pins. Any help would be greatly appreciated!
John

2

When I had a test bed set-up using Duet2 I used the following configuration in the [extruder] block that worked well. I did not define a sercom but instead defined the SPI bus pins:

sensor_type: MAX31865
sensor_pin: PB2  # right port; other possible CS pins : PC24 (left port), PA6 (left port on stacked board), PA5 (right port on stacked board)
spi_software_sclk_pin: PB13
spi_software_miso_pin: PB0
spi_software_mosi_pin: PB1
rtd_nominal_r: 100
rtd_reference_r: 400
rtd_num_of_wires: 2
rtd_use_50Hz_filter: false
3

Thanks! They aren’t software pins though? This didn’t occur to me. I still have to pull the unused chip CS line high correct? Will this also work for the accelerometer on the same bus?
Thanks!
John

4

Yes, you do have to force disable the unused chip based on my experience and on what Kevin noted. I am assuming that you are intending to use an accelerometer on the same SPI bus? I have unfortunately no idea if this will work.

5

OK - got it works! Thanks!
-john

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