I am having a problem with running multiple shields at once via SPI. They are assigned separate CS pins, but share the same SPI connections. The shields are:
- Arduino Uno R3
- SeeedStudio CAN Shield v1.2
- SeeedStudio SD Card Shield v3.1
- Thermocouple via MAX31855
I know that I am able to operate the CAN shield and the Thermocouple IC together with no problem. However, whenever I add the SD shield, the Thermocouple IC looses communication. I remove the CAN shield from the combination and this doesn’t affect anything. It seems to be a problem of the SD card shield working with the thermocouple IC. Does anyone have any experience with this?
I have checked the SPI settings in the various libraries to the best of my abilities and it seems they are compatible. I am intimidated by the complexity of the SDfat library though, so I’m not 100% on it. I am going to attach two versions of my sketch:
- CAN_Thermo_Shield (this works, only CAN shield and thermocouple connected)
- CAN_Thermo_Shield_SD (this doesn’t work, it is supposed to be all shields together)
I will also include copies of the libraries I am using:
Thanks so much for any help you can provide!
CAN Thermo SD.zip (146 KB)