NB: This prototype is done using a discrete chip, you can also use a bluepill board.
This project is a redone from scratch component tester ( see https://www.mikrocontroller.net/articles/AVR-Transistortester ).
The tester is powered by a STM32F103/GD32F103 or GD32F303 MCU. You can also use directly a bluepill board.
The shopping list is (when using a bluepill board)
- Bluepill board
- 1.44' SPI 128x128 screen ( Ebay Link)
- LMV324i Quad op Amp (or any rail to rail quad op amp)
- Rotary Encoder
- AMS 3.3v voltage regulator regulator or similar
- (470 Ohms, 15kOhm, 470kOhm) x3
If you want to use the MCU directly, look at kicad/schematic.pdf Due to the low voltage (3.3v), some mosfet will not be tested correctly.
- Resistor
- Capacitors (from ~ 2 pf to ~ 600 uF)
- NPN and PNP transistors : Hfe, Base-Emitter forward diode voltage
- N & P Mosfet : GS capacitance, RDSon, diode voltage, VgsOn
- Install arduino and cmake
- Checkout the project, make sure you checkout the submodules i.. git clone --recurse-submodules http://xxxxx
- Edit platformConfig.cmake to set the path to your compiler (i strongly suggest to use that ( one) )
- mkdir build && cd build && cmake .. && make
/!\ Important : On mingw dont forget to do dos2unix patches/*.diff
It should work fine on linux and windows/mingw.
By default the firmware is generated for STM32F103C8T6 For the GD32F103 : add -DUSE_GD32F103=True to the cmake command For the GD32F303 : add -DUSE_GD32F303=True to the cmake command
/!\ Important : The code is very close to 64kB, + we need a bit of flash to store settings. As a result, it might not fit inside the GD32F1 or a STM32F1 with really 64 kB of flash.
The code is in two parts :
- Identifying the component
- Probing the component, using only the MCU ADC in single or dual mode.
- For mosfets, since we dont have a DAC on the bluepill, we'll use the charge/discharge of the parasitic FET capacitor to act as a sort of DAC
While accuracy is not bad at all the following restrictions apply :
- Mosfet with VGsOn> 3.3 v will not be probed correctly
- Inductors are disabled, not working properly
- Capacitor of less than 4 pF will not be probed correctly
- Capacitor can be reverse charged with a small current. I'm unsure if that's a big deal. The current is a few mA.
