Allow M144 to turn off the bed heater

ÖrjanE

M144 can only be used to switch the state of the bed heater between active and standby. To reach the off-state it is (as far as I can see) necessary to use the "trick" of setting an impossibly low temperature, using M140. I suggest extending M144 to also cover the off-state.

In analogy with M568, this could be via a (new) parameter A:

M144 A0 ;Turn off bed heater
M144 A1 ;Set bed heater in standby
M144 A2 ;Make bed heater active

Alternatively, the currently used parameter (S) could be extended with "S-1" meaning "off".

Cheers,
Örjan

Dougal1957

Surely if you set the standby temp of the bed heater with M140 R0 or whatever temp you want and then use M144 S0 to put it to standby does what you want.

ÖrjanE

@dougal1957 Sure, using a low standby temperature as a substitute for turning the heater off will do the trick in most situations. However, I can think of a few corner cases where going to the actual off-state may be preferred:

If I do not want to overwrite the standby-temp, for example to make it easy to manually switch it on again
To make it clear in the web interface that the heater is off
To ensure that the heater does not start even if the temp-sensor says it is below zero.

Note that it is already possible to turn the heater off with "M140 S-274". My suggestion is simply to move this functionality to M144 where it (in my opinion) belongs, since M144 is all about switching the bed heater state.

/Ö