Arduino IDE sketch that reads ADC1 very fast, and provides asynchronous (non-blocking) conversions on the ESP32-S3.
I needed to read the ADC way faster, and I needed conversions to be asynchronous. I did NOT need thread-safety.
At the point of writing (esp32 version 1.0.5), the API didn't have me covered.
Performance of regular 'ol functions:
analogRead: 16313 samples/second
analogReadMilliVolts: 10909 samples/second
Performance of these functions:
AnalogReadFast: 109984 samples/second
AnalogReadMilliVoltsFast: 107987 samples/second
Thats 670% over regular analogRead and 980% over calibrated millivolt readings.
fadcInit(<number-of-pins>, <pin>(, <pin>(, ...))
Initializes ADC and pins - don't use regular analogRead and friends after initializing!
analogReadFast(<channel>)
Convert and return result for the specified channel (NOT pin) - corresponding pin must be in the list of pins during initialization.
analogReadMilliVoltsFast(<channel>)
Same as analogReadFast, but returns a calibrated millivolt reading.
fadcStart(<channel>)
Start a conversion and return immediately - don't call unless you know the ADC is not busy.
fadcBusy()
Returns true if the ADC is still converting.
fadcResult()
Return the result of the conversion - don't call unless you know a conversion has completed.
fadcApply(<value>)
Apply calibration on, and convert ADC result (from analogReadFast or adcResult) to millivolts.
Takes a value in the range 0-2**ADC_CAL_RESOLUTION (default 0-4095).