Resting level and swing

/*
  Analog Microphone - resting level and swing           TK27 / /p/tk27

  Wiring. Count from the square pad on the TinkerBlock board, parts
  up, header at the bottom:

    GND    -> GND
    VCC    -> 5V on an Uno; 3V3 on an ESP32, ESP32-S3 or Pico
    NC     -> nothing   (unconnected on the board)
    SIGNAL -> A0 on an Uno, GPIO 34 on an ESP32, GPIO 4 on an
              ESP32-S3, GP26 on a Raspberry Pi Pico

  Arduino IDE
    Tools > Board                 your board, e.g. Arduino Uno
    Tools > Port                  the one that appears when you plug in
    Tools > USB CDC On Boot       Enabled   (ESP32-S3 only)
    No library needed.
*/

// The analog pin SIGNAL is wired to.
// Uno: A0. ESP32: 34. ESP32-S3: 4. Pico: 26.
const int MIC_PIN = A0;

// Uno and Pico only: the ADC's full scale, in mV.
// Uno: 5000. Pico: 3300.
const float FULL_SCALE_MV = 5000.0;
// Several cycles of the lowest sound the block passes.
const unsigned long WINDOW_MS = 50;
const unsigned long CALIBRATE_MS = 1000;

float readMilliVolts() {
#if defined(ARDUINO_ARCH_ESP32)
  return analogReadMilliVolts(MIC_PIN);   // calibrated in the chip
#else
  return analogRead(MIC_PIN) * FULL_SCALE_MV / 1023.0;
#endif
}

void setup() {
  Serial.begin(115200);
  delay(500);
  Serial.println("Measuring the resting level. Keep quiet...");

  float sum = 0;
  long n = 0;
  unsigned long start = millis();
  while (millis() - start < CALIBRATE_MS) {
    sum += readMilliVolts();
    n++;
  }
  Serial.print("Resting level ");
  Serial.print(sum / n, 0);
  Serial.println(" mV");
}

void loop() {
  // The highest and lowest reading in one window.
  float lo = 100000;
  float hi = -1;
  unsigned long start = millis();
  while (millis() - start < WINDOW_MS) {
    float mv = readMilliVolts();
    if (mv < lo) lo = mv;
    if (mv > hi) hi = mv;
  }

  Serial.print("swing ");
  Serial.print(hi - lo, 0);   // peak to peak: louder, bigger
  Serial.println(" mV");
}

"""
  Analog Microphone - resting level and swing, MicroPython
                                                      TK27 / /p/tk27

  Wiring. Count from the square pad on the TinkerBlock board, parts
  up, header at the bottom:

    GND    -> GND
    VCC    -> 3V3   (never 5V: a loud sound takes SIGNAL up to VCC)
    NC     -> nothing   (unconnected on the board)
    SIGNAL -> GPIO 34 on an ESP32, GPIO 4 on an ESP32-S3,
              GP26 on a Raspberry Pi Pico

  Thonny
    Run > Configure interpreter   MicroPython (ESP32) or
                                  MicroPython (Raspberry Pi Pico)
    Nothing to install: machine, sys and time are built in.
"""

import sys
import time
from machine import ADC, Pin

# The GPIO number SIGNAL is wired to. ESP32: 34. ESP32-S3: 4. Pico: 26.
MIC_PIN = 4

WINDOW_MS = 50        # several cycles of the lowest sound it passes
CALIBRATE_MS = 1000

adc = ADC(Pin(MIC_PIN))
ESP = sys.platform == "esp32"         # ESP32 and ESP32-S3
if ESP:
    adc.atten(ADC.ATTN_11DB)          # the full range, to about 3.1 V


def read_millivolts():
    if ESP:
        return adc.read_uv() / 1000   # calibrated in the chip
    return adc.read_u16() * 3300 / 65535


print("Measuring the resting level. Keep quiet...")
total = 0
n = 0
start = time.ticks_ms()
while time.ticks_diff(time.ticks_ms(), start) < CALIBRATE_MS:
    total += read_millivolts()
    n += 1
print("Resting level %.0f mV" % (total / n))

while True:
    lo = 100000
    hi = -1
    start = time.ticks_ms()
    while time.ticks_diff(time.ticks_ms(), start) < WINDOW_MS:
        mv = read_millivolts()
        lo = min(lo, mv)
        hi = max(hi, mv)
    print("swing %.0f mV" % (hi - lo))   # louder, bigger