Ultratronics Firmware 1.0.0: SD thermocouple MAX31855 Conflict

Greetings all,
Using firmware 1.0.0 on Ultratronics board with max31855 thermocouple on TC0 (pin 65),  I finding that when SD card onboard inserted, has conflict with the readings of hotend temperatures, giving 0,0ºC.

SD card is fine.

Looking over the forum I thing I found it could be something related to SPI. I have been trying to find the issue but without success.

Has any one had the same problem?
Any solution?

If could be of any help, attached the firmware .RAR.

Thank you  in advance



  • Information I found regarding same issue on DUE board, from arduino forum:


    But can figure how to extrapolate it to repetier firmware.
  • Hi everybody,

    i am new in 3D printing, and i have a problem with a thermocouple. In the ultratronics as you said, you must connnect the thermocouple on pin 65 (TC0) and the rest of the outputs from the max31855 on D74(MISO) and D76 (SCK).
    I am using the megatronics which include two outputs for thermocouples D65 and D64. I tried to connect directly a thermocouple K on the pin D65, but i don't read any value.

    I have looked at several libraries for thermocouples and in all of them it is necessaryy to define the MISO and SCK pins, so I understand that I need an integrated similar to max31855. This would imply using pins D51, D52 and D53, so i don't understand the utility of D65 an D64 for thermocouples.
    Thank you in advance.

  • There are many megatronics board version. I think they have already a built in chip to convert the signal to something - most likey an analog value. So try selecting type 60 as temperature type and as sensor pin select THERMOCOUPLE_0_PIN or THERMOCOUPLE_1_PIN - I saw they are defined for megatronics so think they are mapped to these 2 sensors. The max31855 is required if they use that chip for temperature conversion,  but AD8494, AD8495, AD8496 or AD8497 requires type 60.
  • Thanks for your answer. As you said, selecting the thermocouple and using an Oversample.h I have get read some values. Now i am triying to adapt it to a real temperature.
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