Radds 1.5, AD8495, Dual extrusion

I'm switching from ramps running marlin to a RADDS 1.5 board and using two thermocouples connected to AD8495 boards.  It looks like there is only a single ADC pin on the RADDS board for connecting a thermocouple, and from the other discussions I've seen the thermistor pins on the RADDS board won't work with the AD8495 boards.  Is there a way to use two thermocouples with the RADDS board, or do I need to replace at least one with a standard thermistor (and not be able to print hi-temp materials with the second extruder)



  • You have 3 more pins you can use, see pins.h -> board 402 for them. There are some comments which pins can be used. Unfortunately they are used to drive a stepper (not sure which one) so you loose a stepper socket but could use an other for same fucntion. Config tool allows selecting which function is on which socket.
  • Ok, would I connect it by just putting a wire/pin into the appropriate hole in the driver socket?  What about modifying pins.h to define the pins that control E4 on the RADDS expansion board like so:

    // Direction pin of extruder 4
    #define THERMOCOUPLE_1_PIN  33 
    // Step pin of extruder 4  
    #define THERMOCOUPLE_2_PIN  35   
    // Enable pin of extruder 4  
    #define THERMOCOUPLE_3_PIN  37 

    Are there changes that would have to happen anywhere else to get on those pins?  Since they are not used without the expansion board, it would be a lot cleaner to solder a header in there and use those pins.
  • Yes, unpluck stepper driver and put it on the pins for dir/step/en.

    Don't use other pins - you need analog pins and not all are analog and you need the analog channel number not pin number for analog reading. Your example does not satisfy even 1 of these condition. You have to use extruder 0 socket and connect extruder 0 to extruder 1 or 2 by selecting that socket in online config tool.
  • Yeah, I was making the assumption that the Dir/Step/En pins would be analog on all the steppers, but I see that's not true. 
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