Timing #63
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Timing #63
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Testing showed that the timer interrupts use each 25us and have a period (at idle) of 50us. That means a processor load at more than 100% at idle with pwm inputs. Turns out the DAC write is using a spin lock for port access which we don't need. See https://forum.arduino.cc/t/esp32-dacwrite-ersetzen/653954/5 Now we are down to 10us for the variable and fixed timer interrupts each.
Resetting the timer frequency takes around 3us. This is unnecessary for the fixed timer. We just need to tell the users to keep the same sample rate for every additional sound (which we kind of already do.) Else you would have issues anyways, when playing e.g. a horn and indicator light ticks at the same time.
Three issues are fixed: 1. in a lot of cases the last sample is not handled. if (sampleCount < sampleLength-1) will omit the last sample. 2. Multiplying the volumes at the end for samples that are not even outputted makes no sense. Actually, since all the sounds have a sound volume it is unnecessary. 3. Adding the samples directly to a buffer is faster than first adding it to variables.
I actually used a script for this. Indicate if you want to have that to automatically convert.
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Fix issues with interrupt timings.