I got my Bluepill STM32F103C8T6 device working in the Arduino IDE with the STM32duino bootloader recently.
I was curious about 16bit PWM as opposed to the crude PWM output of standard Arduinos.
Using core 'maple' from platform in folder: C:\Users\dentaku\Documents\Arduino\hardware\Arduino_STM32\STM32F1
I can do pwmWrite and get a very high resolution 16bit PWM.
I have an optical encoder that updates a variable which I use to change the value of pwmWrite and 2 LEDs conected to PA8 and PA9 fade up and down according to that value.
but... switching over to ST's arduino core which doesn't use pwmWrite but just regular old analogWrite.
Using board 'GenF1' from platform in folder: C:\Users\dentaku\AppData\Local\Arduino15\packages\STM32\hardware\stm32\1.7.0
Using core 'arduino' from platform in folder: C:\Users\dentaku\AppData\Local\Arduino15\packages\STM32\hardware\stm32\1.7.0
In void setup () I set the resolution to 16
analogWriteResolution (16);in my main loop
if (lastValue != encoderValue) { //only update if encoderValue has changed
Serial.print(encoderValue); //NOT println to create two seperate traces in Serial Plotter
analogWrite(LED1, encoderValue); //set PWM amount for LED1 linearly
Serial.print(","); //divider to create two seperate traces in Serial Plotter
analogWrite(LED2, ceil(pow(1.000169, encoderValue) - 1)); // --set PWM amount for LED2 pin exponentially
Serial.println(ceil(pow(1.000169, encoderValue) - 1));
lastValue = encoderValue;
}This seems to give me 16bit PWM output from PA8 and PA9 (LED1 and LED2) but looking at it on my scope it gives me all kinds of weird down-going spikes while the encoder is turning that I don't see at all when using the MAPLE core.
It's fine as long as the encoder is not turning though.
The encoder code isn't spitting out random zeros either because if I plot the value being sent to PA8 and PA9 in Serial Plotter it creates perfectly smooth lines.
I guess I'll try it without the encoder and simply use a for loop to increment and decrement a variable I can analogWrite to those two pins instead, to narrow down the problem.
