Continuous ADC
The ContinuousAdc provides a mechanism for high-frequency, continuous, deterministic sampling of analog voltages for multiple channels (potentially across multiple ADC units, depending on the ESP32 chip used). It does this be enabling the continuous ADC DMA mode and then running its own task which retrieves the data and filters it. When the user calls get_mv(adc_channel_t), it simply returns the most recent filtered value for that channel, if it was configured.