analogRead() and analogWrite()
ADC readings and PWM outputs on each board.
| Arduino Uno | ESP32 | |
|---|---|---|
| analogRead range | 0–1023 (10-bit), 0–5 V | 0–4095 (12-bit), 0–3.3 V |
| Analog pins | A0–A5 | ADC1: GPIO32–39 · ADC2: 0, 2, 4, 12–15, 25–27 |
| analogWrite | 0–255 on pins 3, 5, 6, 9, 10, 11 | 0–255 (core 3.x) or LEDC with any resolution |
| PWM frequency | 490 Hz (980 Hz on 5, 6) | Chosen in ledcAttach() |
Example
int raw = analogRead(A0); float volts = raw * (5.0 / 1023.0);