onboard motor driver work but temp-reading off?



  • Hi,
    my duet2 is working perfectly! All great! Justed stumbled across the possibility to show the heater-temps also of the onboard-motor-drivers, but in my case there is always 0°C(?) even when here in the room are around 25°C? A picture attached: 0_1552174885823_onboard-motor-driver.JPG
    Thankfull for everybody that gives me a clue if I should just ignore it...



  • The driver chips don't report an actual temperature value, they only supply flags for temp warning and over temp. I can't recall off the top of my head what those temp thresholds are, but I think they were around 80c and 125c. So values below that don't register.

    It's generally recommended to use motor current rule of thumb for when to cool the board, and if you want to monitor board temp, the MCU makes for a good proxy. It's also possible to physically attach a thermistor to the chips and monitor that way.

    https://duet3d.dozuki.com/Wiki/Mounting_and_cooling_the_board



  • @lb As @Phaedrux has said, you can't get an actual temperature reading out of the driver chips. If you really want to monitor driver temperature, then you could do what I do and stick a thermistor onto a chip with a small dab of epoxy. You can then use that to control a fan. I covered it in this blog post but it's a long time ago and a bit out of date https://somei3deas.wordpress.com/2017/04/18/stepper-motor-and-electronics-cooling/.

    Things are a bit simpler now - you don't have to create virtual heaters and you can give them meaningful names.


Log in to reply