Analog Sensor Integration MANTA M8P

[mykepredko]

@AlSabra

What is the best way to capture raw ADC values from an analog pin on an STM32 MCU in Klipper?

Do you really need “raw ADC values” or do you actually need ADC values that indicate the light level shining on the phototransistor?

I use the adc_temperature statement with a couple of resistors to monitor the input voltage going into a controller board as detailed here:

Power Supply Voltage Monitor Hack

In recent weeks, there have been a couple of issues that I have wondered were due to power supply “sagging” with the issue being that this something that happens over time and unpredictably. Understanding if this is the issue can be expensive as DC power supply monitors are instruments with a somewhat limited market. Thinking about it, I wondered if a Klipper based printer itself could monitor the power supply voltage through an unused thermistor connector - I realize that this means somewhat …

This is being used as a basis for the functional test suite I’ve been working on to check the input voltage values and, more importantly, the ADC circuitry on the controller board.

Using a macro, I can test the voltage values (which are derived from the measured ADC voltages in the adc_temperature statement and respond accordingly:

[gcode_macro vintest]   
gcode:
    {% set VINMON_VALUE = ( printer["temperature_sensor PS_voltage"].temperature )|float %}
    RESPOND TYPE=command MSG="VINTest: { VINMON_VALUE }V"
    {% if 23.5 > VINMON_VALUE %}      
        RESPOND TYPE=error MSG="VINTest: Voltage BELOW 24V"
    {% else %}
        {% if 24.5 < VINMON_VALUE %}      
            RESPOND TYPE=error MSG="VINTest: Voltage ABOVE 24V"
        {% else %}
            RESPOND TYPE=command MSG="VINTest: PASS"
        {% endif %}
    {% endif %}

It may take a bit of work to determine the conversion value but it works very well and, in my case, the “temperature” values accurately correspond to the actual voltages input into the board.