Basic Information: Printer Model: Sovol SV06 MCU / Printerboard: Original MCU + Raspberry Pi 4 as secondary MCU klippy.log Hello, I am trying to control a chamber heater with a relay connected to the RPI4 host via GPIO. (there are 77 °C thermal fuses connected inside the chamber between the h…

[image] Heater Bed Temperature is increasing without heating I guess this is a starting point to understand that. Configuration reference - Klipper documentation Search [verify_heater]. Good luck, hcet14

[image] sebokie: What am I doing wrong here? Nothing. Unfortunately, this is a long-standing issue with this sensor type. I can only recommend using a different sensor, e.g. a plain NTC for your purpose.

Hello, Thanks for the answers. I worked around the problem by disabling the check in src\gpiocmds.c in the function “command_queue_digital_out” and rebuilding for the rpi. Now I can set a temperature for the chamber and the heater is correctly managed: I can see that it goes off when the (tempera…

Unfortunately not. Also the initial report contains no real pointers: BUG?: Chamber Heater with DS18B20 Temperature Sensor generates "MCU 'mcu' shutdown: Scheduled digital out event will exceed max_duration" failure · Issue #5189 · Klipper3d/klipper · GitHub Maybe @koconnor can give some hints wher…

Thank you @Sineos for the links. I will check them. I tried to launch a print with a temperature for the chamber heater after adapting the PRINT_START macro. The temperature is being set and the heater starts, however during the pre-print heating phase I get the error “Missed scheduling of next di…

The Klipper heating code was designed around temperature sensors that provide an update every 300ms. The ds18b20 sensor can only provide updates once every second or so. Thus the two are not compatible. It might be possible to rework the host code to better hanle slower updating sensors (the code…

Hello, Thanks @koconnor for the information. I read the code in heaters.py but I don’t see any link with the error messages given by the web interface (“Missed scheduling of next digital out event”) so I gave up. I tried now to use a Raspberry Pi Pico that I bought, with this temperature sensor: h…

You cannot simply connect a NTC to an ADC. It needs a voltage divider with an accurate (and temperature stable) resistor. See How Easy Is It to Use a Thermistor?! | Arduino Project Hub for an example (surely you will find an abundance of examples, was more or less the first hit)

So I soldered a 10K resistor between a wire coming from ADC_VREF and a pin of the thermistor that is connected to GP28/ADC2. The other pin of the thermistor is connected to Ground/AGND. I tried every possible predefined sensor type in Klipper and none gave good values. Then I used this table found…

Have you set the 10K as “pull-up”? Ref to Configuration reference - Klipper documentation

Controlling a chamber heater through a relay connected to RPI4 via GPIO and monitored with a DS18B20

General Discussion

hcet14 October 22, 2023, 2:51pm 2

Good luck, hcet14

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Controlling a chamber heater through a relay connected to RPI4 via GPIO and monitored with a DS18B20

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