I want to read three MAX31586s using a Raspberry pi 3B. Two are connected on the spi0 and I can configure the maxtherm on config.txt to work. For the third one, maxtherm doesn't work with spi1, at the boot it report an error on the spi mode non supported on spi1. Any suggestion? Another question related to maxthem: where I can found the documentation of it? I would like to change the configuration of the max31586, like notch filter, average, etc, and request the start of correction. Thank you.

  • Do you really mean MAX31586? or is it MAX31856? Also - have you read the documentation on the device tree configuration for SPI and MAX31856 in the README documentation for config.txt?
    – Seamus
    Jun 26, 2023 at 21:59
  • Try writing in paragraphs. Include details of connections and what code you are using.
    – Milliways
    Jun 26, 2023 at 22:58
  • Yes, it is MAX31856 my mistake. The overlay is working but I can only configure the type of thermocouple and the spi. By looking, for example, /sys/bus/iio/devices/iio:device1 I can read all the parameters but I can not change the value. For example: 'cat in_temp_filter_notch_center_frequency' return 60. How I can change the value to 50? 'echo 50 > in_temp_filter_notch_center_frequency' return 'Permission denied' Jun 27, 2023 at 20:15

2 Answers 2


SPI1 does not support mode 1 or 3.

  • Thanks, this explain why spi1 doesn't work with MAX31856. Jun 27, 2023 at 20:18

I just found libiio. I managed to change 'in_temp_filter_notch_center_frequency' by using 'sudo iio_attr -c max31856 temp_ambient filter_notch_center_frequency 50'. I will try to use it in C/C++

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