Temperature dips
Since a few months I have a strange behavior of Extruder temperatures: Every few minutes the temperature reading drops to 0°C.
I first thought that it would b an issue with the PT-100 or the amplifier board I had in my hotend. Now I just found my old thermistor again, connected it to another input than the PT-100 - and it shows the same behavior.
I even tested the thermistor directly plugged into the mainboard, so that no wire breaks or loose connectors could be the reason.
This is with PT-100:
And this is now with my trusty old thermistor:
Any Ideas?
Cheers,
Simme
I first thought that it would b an issue with the PT-100 or the amplifier board I had in my hotend. Now I just found my old thermistor again, connected it to another input than the PT-100 - and it shows the same behavior.
I even tested the thermistor directly plugged into the mainboard, so that no wire breaks or loose connectors could be the reason.
This is with PT-100:
And this is now with my trusty old thermistor:
Any Ideas?
Cheers,
Simme
Comments
In the following graph I heated the extruder, then switched it off and disconnected the main PSU.
So even when the Arduino (Due) was only powered via USB (from raspberry pi with repetier-Server), the same dips occur.
Any further ideas?
Would it help to attach a capacitor to the connector of the thermistor?
Cheers,
Simeon
Shorts maybe but where?
Does this also happen when motors are off and you are not heating? These may cause cross talk changing resulting analog value, also smoothing normally reduces the effect.
Last thing would be to change the analog input port in case the port has some problems.
And i have used shilded cabels + the printer was in a park position
If that dosent work il try to use a capacitor
BTW: What temperatures does it drop to? I mean if just one letter is missing it could be communication, but if it always drops to 0 or whatever minimum is for the thermistor table it is the analog input getting the bad voltage.
Ore from 200° to 5° and then back.
So should i just try a Capacitor parralle to the Voltage input of the Pt100 sensorboard?
At first it was in the Park position with Motors turned off including with the capacitor.
After that i heated up and after cooling down i comlietlie removed the Thermistor.
Then i just powerd the board via USB.
And now its clearl than not my Hardware has a Problem. Its the Firmware.
But what can i do?
Did it work before or is this since the beginning? If it is only since some time my guess would be a defect on the chip, otherwise you would need to check if you do not use the same pin e.g. as output somewhere to be sure.
It works in my Case, Iam so Happy .
Thanks for your help
Glad it is now working.