Initial Low Voltage Autopause and Stack Underflow Errors

  • So I just finished building a DIY 3D printer, a BLV MGN Cube, and I have been tuning it for a few days, and it has been printing fine. However, throughout tuning it, I have encountered some problems from the Duet 2 Wifi board. Nothing terrible, but annoying nonetheless. When my printer has been idling, with nothing heated, for a bit of time before I start a print, I always get a weird "low voltage" trigger (I think? my hotend/tool 0, which is a genuine E3D v6, has been heating up and functioning just fine) , despite the Duet board reporting a 24.0 Volt input in the web control, which causes the print to autopause, and then causes the motors to act weirdly (as in barely moving, if at all moving) if I resume the print from that autopause. To get around this, I have to emergency stop the printer, so it restarts, and then I can immediately run prints just fine with no triggered autopause. Also, as a weird side error, I randomly get the error: "Error: Pop(): stack underflow!". It doesn't happen consistently, and I can't figure out what might cause it. Could someone please help me with fixing these errors?


    Extra information about my board setup, which is a Duet 2 Wifi v1.04, just in case:

    Firmware Electronics: Duet WiFi 1.02 or later
    Firmware Version: 2.02(RTOS) (2018-12-24b1)
    WiFi Server Version: 1.22
    Web Interface Version: 1.22.6

  • if you have not restarted the duet, post the output of M122.

  • Here's the start of a print. I ran M122 twice: once after the low voltage pause, and the after the reset, once I get a print started, after the stack underflow error. I compiled that part of the console in this text file.

  • Supply voltage: min 23.3, current 24.1, max 24.6, under voltage events: 0, over voltage events: 0,
    Supply voltage: min 20.7, current 23.9, max 24.8, under voltage events: 0, over voltage events: 0, power good: yes

    There was no undervolt event in both cases. Though a drop to 20V is significant. This could mean that either the psu is not enough for your setup, or its damaged.

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