Arduino Uno R3
| Chip | ATmega328P (AVR) |
|---|---|
| Flash | 32 KB |
| PSRAM | None (2 KB SRAM) |
| Max LEDs | 60 |
| Audio | — |
| Display | — |
| Touch | — |
| Storage | None |
| Network | — |
| Update modes | Standalone (WiFi/OTA) |
Wiring
Section titled “Wiring”| GPIO | Can do | Notes |
|---|---|---|
2 | in / out | D2 |
3 | in / out / PWM | D3 |
4 | in / out | D4 |
5 | in / out / PWM | D5 |
6 | in / out / PWM | D6 — default LED data pin |
7 | in / out | D7 |
8 | in / out | D8 |
9 | in / out / PWM | D9 |
10 | in / out / PWM | D10 |
11 | in / out / PWM | D11 |
12 | in / out | D12 |
13 | in / out | D13 — built-in plain LED |
14 | in / out / ADC | A0 |
15 | in / out / ADC | A1 |
16 | in / out / ADC | A2 |
17 | in / out / ADC | A3 |
18 | in / out / ADC | A4 |
19 | in / out / ADC | A5 |
Reserved pins — leave these alone
GPIO 0— D0 — UART RX (serial)GPIO 1— D1 — UART TX (serial)