GRBL LPC air assist does not switch off

[Alf3181 (Christian)]

Hello,
I have GRBL LPC on SBase board.

If i start one job with air assist,
the air assist starts to beginn.
After the job, the air assist dont switch off.

if i have a second layer and config layer two with air assist off.
the air assist dont geht off by second layer.

I have air assist configure to M8.
If i use M7, the air assist dont start on any ports.

I have magnet valve for the assist on pin 2.6.

what can i do that Lightburn switch the air assist off after lay job?

[LightBurn (Oz)]

Air assist is usually M8 and M9. If M9 does not turn off the port for you, you might need a pull-down resistor on the port. LightBurn is emitting the commands correctly - here are three small shapes, with the first and last using air assist, and the middle one not:

; LightBurn 0.9.09
; GRBL device profile, absolute coords
G00 G17 G40 G21 G54
G90
M4
; Cut @ 185 mm/sec, 14% power
M8
G0X95Y113.35
G1X80Y135S140F11100
G1X95Y156.65
G1X125
G1X140Y135
G1X125Y113.35
G1X95
; Cut @ 70 mm/sec, 80% power
M9
G0X190Y110
G1Y140S800F4200
G1X240
G1Y110
G1X190
; Cut @ 15 mm/sec, 50% power
M8
G0X170Y100
G1X210S500F900
G1Y70
G1X170
G1Y100
M9
G1S0
M5
G90
; return to user-defined finish pos
G0 X0 Y0
M2

You can see an M8 / M9 pair around both the first layer and the last layer, so air assist is turned on for the first layer, off for the 2nd, on again for the 3rd, then off at the end of the file.

[Alf3181 (Christian)]

Thanks you for your support.
The problemm is solved.
In the GRBL LPC in time, there is a bug.
Some freinds have the for me the code debug and new compiled.
Today i have no problems with the debugt firmware version.