Arduino for STM32

that old 'roger's bootloader' may work too.
https://github.com/rogerclarkmelbourne/ ... bootloader
you could try flashing a stock firmware from there. it is normally for stm32f103c8. But f103rc may work, no guarantees though.

for solar cells, i think the output for each cell is about 0.7v. But some modules have a number of them connected in series that give those higher voltages. If indivitual cells can be used, 4.2v is about 6 cells in series. This would likely make it more managable, e.g. one could connect exactly 6 ce...

you can use a hardware timer. https://github.com/stm32duino/wiki/wiki/HardwareTimer-library HardwareTimer timer(TIM1); void readAdc() { uint16_t value = analogRead(pin); ... } void setup() { timer.pause(); timer.setoverflow(15000,, MICROSEC_FORMAT); timer.refresh(); timer.attachInterrupt(readAdc); t...

your formula looks right, the adc won't get the full 3.3v at the top in part due to the various electronics (e.g. transistors in there) being a little less than 3.3v looks normal. As things I do normally won't need very high precision or accuracy, i'd make do other ways you could verify things is to...

Vrefint is in the data sheet https://www.st.com/en/microcontrollers-microprocessors/stm32f103c8.html 5.3.4 Embedded reference voltage VREFINT min 1.16, typ 1.2 max 1.24 v that is the adc reading you get for 1.2v so assuming a linear range, and that the top is vdd 3.3v by linear projection : adc read...

Serial monitor is normally Serial.println("hello world"); you can replace that with anything you want to print, so you could print anything to have it sent back to your serial monitor to look at I'd suggest copy that library into the project folder both the include and cpp file, then put t...

google search for RM0008 stm32f103 you should get this https://www.st.com/resource/en/reference_manual/cd00171190-stm32f101xx-stm32f102xx-stm32f103xx-stm32f105xx-and-stm32f107xx-advanced-arm-based-32-bit-mcus-stmicroelectronics.pdf look in the chapter for ADC, look under temperature sensor section i...

if you can output to the serial monitor I'd suggest patch Serial.print() statements in the code, to see what is happening there are some things that is a little curious https://github.com/bmellink/IBusBM/blob/master/src/IBusBM.cpp#L84 #if defined(_VARIANT_ARDUINO_STM32_) void IBusBM::begin(HardwareS...

check the core you used. it may help to have #include <Arduino.h> in there, normally not needed.

that should work for 'official' core, e.g.
on datasheet, section 5.3.4 Embedded reference voltage
https://www.st.com/resource/en/datashee ... f103c8.pdf
that is the adc value you get for the internal voltage 1.2v