Main board used as expansion board doesn't handle idle current percent

[dc42]

If a main board is used as an expansion board then changing the idle current percentage on the master board using M906 with the I parameter doesn't affect the idle current percent used on the slave board, which remains the default 30%.

[dc42]

Provisional fix implemented in 3.6 source code. This could be back-ported to 3.5 if we do a 3.5.3 release.

[mbalajew]

This is great, thank you. Did you need any help with testing?

[dc42]

Fix now implemented in 3.5-dev source code too. @mbalajew which Duet are you using?

[mbalajew]

@dc42 I'm using two Duet 3 Mini 5+ boards

[dc42]

@mbalajew have you tested this fix in 3.5.3?

[mbalajew]

Hey @dc42, yes, unfortunately it's still an issue on 3.5.3

[droftarts]

I have tested this in both 3.5.3 and 3.6.0-beta.1, and both appear to work correctly for me, with the axes on the mainboard-as-expansion-board controlling normal axes.
@mbalajew are you controlling normal axes, or extruders, on the Mini 5+ expansion board?

Test setup: two Mini5+, running 3.6.0-beta.1. First board is on my normal bedslinger, second board has 1 motor attached to driver 0, and only has M954 A60 in its config.g. Configured motor as U axis, with same parameters as X axis.

Test: Initially M906 I30 and M84 S30 were set. I changed M84 S10, and idle timeout dropped to 10 seconds, on motors connected to both boards following a move of that axis (X and U tested). Changed M906 I100, motors on both boards maintain 100% current. Other M906 I# and M84 S# values tested, with the correct behaviour observed. So appears to be working correctly in 3.6.0-beta.1.
Reverted firmware to 3.5.3 on both boards, and ran tests again. Same result, so it seems to working as expected.