The SAMD21 based Arduino boards have a 10 bit DAC, so naturally I wanted to generate a sine wave! Some years ago when I was teaching microcontrollers I had students build a DAC using a resistor ladder. The microcontroller, a 68HCS12, used a timer interrupt to advance the value to the DAC by indexing a …
The ARM-based (SAMD21) Arduino Nano 33 IoT might have been rushed into production based on a somewhat deficient assignment of Timer/Counters to PWM pin functions. Arduino documentation claims 11 PWM pins: D2, D3, D5, D6, D9, D10, D11, D12, A2, A3, and A5. However the following is not documented: This means there are only really …
With the AVR-based Arduino boards, doing an input capture in a timer/counter (to time stamp a signal edge) was very simple, although not supported in the Arduino library. It’s just three instructions to completely configure. With the SAMD21 it becomes a major programming effort to get an external signal to the timer/counter. So 14 instructions. …