Comparing two temp sensors

silveroranges

Hello!

I printed off a vent that takes hot air from the top of my chamber and sucks it to the bottom. I have two temp sensors, one at the top of the chamber, and one at the bottom. Is there a way to compare these two values and turn on the blower only when they vary by x amount?

On a related matter, for redundant temperature sensors like they have on the mosquito magnum, how would that be set up in the firmware? Where if one fails, it pauses the print with the option to continue.

chrishamm

@silveroranges It isn't possible to configure differential temp sensors AFAIK. What you could do is to have some code in daemon.g where you compute the difference between two sensors and then turn on the fan conditionally. Example for daemon.g

if sensors.analog[1].lastReading  - sensors.analog[2].lastReading > 10
  M106 P1 S1 ; turn on fan 1 at 100%
else
  M106 P1 S0 ; turn off fan 1

where the sensor #1 is at the top and sensor #2 is at the bottom. RRF already pauses the print automatically when a heater fault occurs. But you could still set up extra heater protection monitor using the second sensor, see M143 for further details.

silveroranges

@chrishamm I appreciate the help, it worked fantastic!

dc42

@silveroranges to reduce the load on the file system, it's best to wrap that macro in a while-loop and include a G4 delay of a few seconds in it.