Hall_filament_width_sensor values not changing

General Discussion
1

I followed this guide to build a filament-width-sensor: followed this guide Printables (V3!)

I used Thermistor-Pins on an BTT Octopus and got 3.3v from WiFi module
when I move the magnet / insert test-bolts to calibrate the values don’t change (values are jumping 2-3 all the time)
when I unplug a sensor-pin or voltage I get different values so I think connection could be correct

QUERY_RAW_FILAMENT_WIDTH
empty: ADC1= 8396 ADC2=8409 RAW=16805
empty: ADC1= 8395 ADC2=8408 RAW=16803
1.5mm: ADC1= 8393 ADC2=8407 RAW=16800
2.0mm: ADC1= 8393 ADC2=8407 RAW=16800
unplug2: ADC1= 8394 ADC2=9993 RAW=18387
unplug1: ADC1= 9993 ADC2=8408 RAW=18401

using 2 49E Hall Effect Sensors (https://www.amazon.de/gp/product/B08PBL81MC)

or is just the magnet not strong enough? distance to the sensors is about 3 mm while I used a 6x3 magnet

[hall_filament_width_sensor]
adc1: PF6
adc2: PF7
default_nominal_filament_diameter: 1.75
measurement_delay: 125
min_diameter: 1.0

[menu __main __filament __width_current]
type: command
enable: {‘hall_filament_width_sensor’ in printer}
name: Dia: {‘%.2F’ % printer.hall_filament_width_sensor.Diameter}
index: 0

[menu __main __filament __raw_width_current]
type: command
enable: {‘hall_filament_width_sensor’ in printer}
name: Raw: {‘%4.0F’ % printer.hall_filament_width_sensor.Raw}
index: 1

2

Original design https://www.thingiverse.com/thing:4138933

https://www.klipper3d.org/Hall_Filament_Width_Sensor.html

1 Like
3

changing from 3.3V to 5V did the change :slight_smile:
in the desciptions on thingiverse and Printables they use RX/TX pins for sensor connection on SKR 1.4 but on Octoboard I get the error this are no valid ADC pins - I think the stepper-dirver-pins should have an ADC-pin also? I didn’t found the ID’s for this singe pins… would be great to get back my termistor pins ~~

4

Get the datasheet of your printerboard’s chip, e.g. https://www.st.com/resource/en/datasheet/stm32f446ze.pdf

There you will find a table with the pins functions, e.g.

image
image1195×919 101 KB

For any one reading this: DO NOT do this before carefully checking your boards capability. In fact most pins only tolerate 3.3V and putting them to 5V may damage your board.