Trouble assigning filament sensor after using pin for GPIO

[Piet]

Hi all,

I have a question about assigning a filament sensor to an input after using it for a GPIO pin.
I'm using a rotary magnetic encoder as filament sensor, this is placed inside my extruder and is declared as a pulse generating filament sensor.

Now i'm trying to write a macro for loading the filament into the extruder and priming the nozzle. To do this i remove the filament sensor in the macro, read the output of the sensor (0 or 1), and keep extruding until that changes. After that i extrude an extra amount to prime the nozzle and remove the GPIO and try to redefine the filament sensor.

However if i do this it throws this, Error: M591: Pin 20.io1.in is not free, even tho i
removed it using: M950 J9 C"nil" and echo exists(sensors.gpIn[9]) returns false.

Does anyone know of a way to fix this or should i abandon this macro?

G91 															; relative posisitioning

M591 D0 P0														; remove existing filament sensor
M950 J9 C"20.io1.in"											; add GPIO at filament sensor pin

var sensorInput = sensors.gpIn[9].value							; read current filamentsensor output

M291 P"Load filament into the drive gears." S3					

while (sensors.gpIn[9].value == var.sensorInput)				; while filamentsensor value does not change keep extruding
	G1 E1 F1800
	if iterations > 50
		M291 P"Loading filament has timed out" S2
		M591 D0 P7 C"20.io1.in" L0.061 R80:120 E1 S1
		G90
		M99

echo "Filament sensor has been triggered. Priming nozzle."		
M400
G1 E110 F300													; prime nozzle

M400

G90

M950 J9 C"nil"													; remove GPIO
echo exists(sensors.gpIn[9])
M591 D0 P7 C"20.io1.in" L0.061 R80:120 E1 S1					; add filament sensor again

M291 P"Filament has been loaded." S2

Thanks in advance,

Piet.

[dc42]

@piet which firmware version are you using? A bug in this area was fixed in firmware 3.3.

[Piet]

@dc42 Im using version 3.4.0beta3 in SBC mode

[dc42]

@piet thanks, I'll test that.

[dc42]

@piet I confirm there is a bug. M950 J# C"nil" does not release the port if it is on an expansion board. This will be fixed in the next beta release of the expansion board firmware.

As a workaround, if you have a spare IOx.IN port on the same expansion board, then instead of deleting the GpIn port using C"nil" you could reassign it to that pin.

[Piet]

@dc42 Alright, thanks for the help!