Thermistor pin swap

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MateMago
Posts: 4
Joined: Sat May 25, 2019 9:41 pm

Thermistor pin swap

Post by MateMago » Tue May 28, 2019 5:37 am

Hello everyone,

I am trying to upgrade my i3 Pro B to use 2 extruders. It mounts a GT2560 A+.
I flashed the i3 Pro C firmware, but the second thermistor input seems broken: it measures 198°C with no thermistor plugged.

- If i shortcut it measure something like 350°C
- if I plug the thermistor and heat up the hot end the temperature rises, but obviously its not a real measure.
- I thought it was a problem with the pullup resistor so I changed it with no luck.
- The resistance and voltage on the pins are 0.57KOhm and -0.56V (on the other input which works fine are 5.7KOhm and 4.90V).

To easy fix this problem without changing the board I was wondering if there are any other unused pins that I can use as thermistor input (changing the pins.h file). The only working solution I found is to renounce to the heated bed and use that input for the second extruder thermistor but I really don't want to. Thank you in advance for all the help.

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William
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Joined: Tue Jun 07, 2016 9:38 am

Re: Thermistor pin swap

Post by William » Tue May 28, 2019 9:44 am

-Keep your mind and try to test it. :)
-Everything will be fun!-Support all Getech printer.
-You can ask me the questions and I will kindly reply.
-Respect others is the best way you can get help!

MateMago
Posts: 4
Joined: Sat May 25, 2019 9:41 pm

Re: Thermistor pin swap

Post by MateMago » Tue May 28, 2019 2:42 pm

I followed this guide william, but my problem is that the input for the second extruder thermistor is broken on the board, so I need another pin to use as for the input of the second thermistor. I know there are plenty of unused pins on the GT2560 a+, but I don't know which I can use as a thermistor input.

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_kaktus_
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Re: Thermistor pin swap

Post by _kaktus_ » Sun Jun 02, 2019 2:12 pm

Hi.
:mrgreen:

You need to plug in an analog input with ADC functionality.

You will find the controller board schematic and the µC data sheet helpful.

Alternatively, this forum. ;)
On the forum I help to use the rod, I don't give fish.
Geeetech Prusa I3 M201 Dual extruder Mixcolor 3D printer, bought 2017-12-19, already built, in the cognitive and improvement phase
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