Answer to "How does one use the PT100 Amp Board with a 3.3v controller, eg RADDs"Please see the following contents of a thermistor header file I named thermistor_22.h (can be any unused thermistor number). This was done for the BTT V1.4 boards using a E3D PT100 amp with the INA826 chip but may apply to other similar controller boards. See details of hardware & software install in the file text. I hope this helps. /** (1) Marlin 3D Printer Firmware (1) Copyright (c) 2020 MarlinFirmware https://github.com/MarlinFirmware/Marlin * (1) Based on Sprinter and grbl. (1) Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm * (1) This program is free software: you can redistribute it and/or modify (1) it under the terms of the GNU General Public License as published by (1) the Free Software Foundation, either version 3 of the License, or (1) (at your option) any later version. * (1) This program is distributed in the hope that it will be useful, (1) but WITHOUT ANY WARRANTY; without even the implied warranty of (1) MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the (1) GNU General...
Answer to "How does one use the PT100 Amp Board with a 3.3v controller, eg RADDs"Hi, The E3D PT100 board can be run at 3.3V. The other thing is that most 3D printer controller boards have a 4.7K pullup on the thermistor input. This creates an offset and skews the temperature reading. This is why people that just try to run the PT100 amplifier at 3.3V get strange readings. All that is needed is a proper thermistor translation table to operate correctly. I had to do this for the Bigtreetech 1.4 board and I already had the E3D board from an older machine. I’m not sure how to pass along files on this forum but I have the header file “thermistor_22.h” and can share with anyone that is interested. Update (07/09/2020): Please see info on Github: https://github.com/johnny49r/BigTreeTech