Electrical – How to change Voltage Reference in STM32 NUCLEO-F103RB board Analog Input from 3.3V to 5V

analogstm32stm32f103voltage measurement

I have a joystick module for Arduino connected to my PA0 pin (that pin is set as ADC1_IN0). I would like to read the voltage from that pin but there is a problem. The voltage on which the joy-stick module operates is 5V and HAL functions I'm using to read Analog values are referencing it against 3.3V, which renders part of the module (which is essentially a potentiometer) useless and nonfunctional as the value given measured is gonna be simply 4095. Here is the code that I have in the while(1) function in main():

      HAL_ADC_Start(&hadc1);
      HAL_ADC_PollForConversion(&hadc1, HAL_MAX_DELAY);
      raw = HAL_ADC_GetValue(&hadc1);

How can I make it reference this voltage against 5V so I can get the full reading?

Best Answer

The STM32 ADC does not support reading voltages that are larger than the supply voltage. Either change the joystick reference voltage to match the STM32 voltage or divide the joystick voltage down with resistor divider.

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Electronic – Making PWM from 2 Analog input in MSP430G2231

You are not waiting for the ADC to finish the conversions. You would have to do something like this:

 for (;;)
{
  ADC10CTL0 &= ~ENC;

  while (ADC10CTL1 & BUSY);                 // Wait if ADC10 core is active
    ADC10SA = 0x200;                        // Data buffer start
    P1OUT |= 0x01;                          // Set P1.0 LED on
    ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
    __bis_SR_register(CPUOFF + GIE);        // LPM0, ADC10_ISR will force exit
    P1OUT &= ~0x01;                         // Clear P1.0 LED off
 }

}

You should read the user guide - chapter 20 (I think) ADC10 and look at the code examples on ADC10 with DTC

Electronic – Flashing STM32 Nucleo from Raspberry Pi

Linux thinks it's just some external storage, and holds back (caches) writes while it's mounted. You can try to

umount the Nucleo interface after copying, forcing everything to be written back
issue a sync command after copying
mount it with -o sync to disable write caching.

The first two methods are preferred over -o sync (as long as they work), because writes are still cached until the system is told to write everything, using up fewer flash write cycles.

If none of the above works reliably, then install openocd or texane st-link on the pi, and use that for flashing.

Best Answer

Related Solutions

Electronic – Making PWM from 2 Analog input in MSP430G2231

Electronic – Flashing STM32 Nucleo from Raspberry Pi

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