Troubleshooting Inductive Sensor for Z-Probe

MurphDurtay

Hi I'm setting up my new printer with a Duet 3 wifi 5+ and am having trouble getting the Z-Probe to trigger.

This is the sensor: https://www.amazon.com/gp/product/B07H6CHFB8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I followed this guide for the NPN Normally Open Sensor:
https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe

I have the Blue wire connected to the GND and the Brown wire connected to 12V on the connector to the Wifi module side of the 3 pin Lazer/VFO header. The black wire is connected to io-3 in and I have configured the config file according to the instructions in the above guide.

I haven't tried homing yet but with the printer plugged in and running I stick a steel ruler directly under the sensor and the built in LED does not light up. I've been assuming the LED lights up when the sensor is triggered and sending a signal through the Black wire. I'm trying not to crash my bed into my nozzle so I want to be sure it's working before I home Z.

MurphDurtay

After Troubleshooting I found that whether there is steel directly below it or not the black wire has 24.2(Vin) between it and the ground it is connected to. Is that normal behavior? The full Vin going to the input pin doesn't seem right to me, I expected 0V when not triggered then 5ish volts when triggered. Maybe the sensor is just bad?

jay_s_uk

@MurphDurtay the output signal matches the input voltage. so if you're feeding it 24v it will output 24v. the IO pins are rated to 30v on the duet 3 mini

MurphDurtay

@jay_s_uk said in Troubleshooting Inductive Sensor for Z-Probe:

@MurphDurtay the output signal matches the input voltage. so if you're feeding it 24v it will output 24v. the IO pins are rated to 30v on the duet 3 mini

But shouldn't the black wire out put voltage only when metal is below the sensor?

jay_s_uk

@MurphDurtay on my pinda probe its the opposite. voltage unless triggered

MurphDurtay

Figured it out, I'm an idiot.... I was holding metal to the side opposite of the wire when I should have been holding it to the larger side, the one with the crosshairs....