Error : M42 : parameter ‘p’ too high

Jimmykc

My Duet3 board is MB6HC Revision 1.0, and the firmware is 3.01-RC9.
If I configure GPIO P15, I send “M42 P15 S1” command.
The duet3 board will show “M42 P15 S1”.

If I configure GPIO P16, I send “M42 P16 S1” command.
The duet3 board will show “Error : M42 : parameter ‘p’ too high”.

Why do I only configure the GPIO less than P16 ?
If I want to use one Duet3 main board and two Duet3 expansion boards, I will not configure all GPIO.

chrishamm

Are you really configuring 16 different GPIO pins? RRF lets you define 16 input and 16 output pins, which is more than enough is for most applications. M42 P defines the index and you can choose an arbitrary number between 0 and 15 for that.

Jimmykc

@chrishamm Yes, I am really configuring 16 different GPIO pins because I use a Duet3 main board and two Duet3 expansion boards. The Duet3 main board has 9 GPIO. The two Duet3 expansion board have 12 GPIO. Total GPIO is 21 is more than the limit of GPIO.

dc42

@Jimmykc, I can increase the limit. May I ask what you are using all these GPIO pins for? How many do you need?

Jimmykc

@dc42 Thanks for your help, but I am sorry.
I can’t tell you what function we need.
Now I develop the controller for our product.
The system is based on the main board and two expansions board in the future.
I try all G code and M code in the beginning, and I have to find the max limit of duet3 board IO if we want to use them to control new functions.
Could you increase the limit to parameter ‘p’ to 30 ?
The parameter ‘p’ is 30 is enough for me. Thanks a lot again.

dc42

I'll increase it to 32 in RRF 3.01-RC11, subject to sufficient RAM on the tool board.

Jimmykc

@dc42 I am very looking forward to your success. Thank you.