Tool pids affected by bed pids

Traumflug / Teacup_Firmware

Firmware for RepRap and other 3D printers

http://forums.reprap.org/read.php?147

GNU General Public License v2.0

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Tool pids affected by bed pids #301

Closed phord closed 6 years ago

phord commented 6 years ago

I noticed if the bed heater is maintaining a setpoint then the tool heater drifts by +/- 5 degrees. But if the bed heater is solid-on or solid-off, the tool temperature only drifts half a degree. Why are the correlated? Is it real or is it a read inaccuracy?

screenshot from 2018-07-07 21-10-01

triffid commented 6 years ago

power supply noise, or poor load regulation?

Wurstnase commented 6 years ago

I had some years ago a similar issue. In my case was it a bad layout from the shield. A switching regulator was close to the ADC line.

phord commented 6 years ago

Could be. Cheap-o RAMPS 1.4. I guess I know even better why we have TEMP_EWMA now. :imp:

phord commented 6 years ago

Hm. Obviously I should move my Gen7 board over since I no longer use the printer it is attached to. And because this RAMPS 1.4 may be a fire hazard.