ESP32-S2-DevKitC-1, 44 pin pinout
ESP32-S2 board. Pick ESP32S2 Dev Module in the Arduino IDE. 23 of its header GPIOs are free of boot, flash and USB duties.
S2
3V3
GND
3V3
TX
RST
RX
4
1
5
2
6
42
7
41
15
40
16
39
17
38
18
37
8
36
3
35
46
0
9
45
10
34
11
33
12
21
13
20
14
19
5V
GND
GND
GND
Field notes
- The ESP32-S2 has Wi-Fi but no Bluetooth.
- Two USB ports: a micro-USB UART bridge, the default, and the chip's native USB on GPIO 19 and 20.
- The addressable RGB LED is on GPIO 18.
- GPIO 46 is input only. GPIO 17 and 18 have the chip's two DAC outputs.
- The current DevKitC-1 uses the ESP32-S2-SOLO-2 module with 8 MB flash and 2 MB PSRAM.
Analog and Wi-Fi
Wi-Fi also uses ADC2. The driver arbitrates, but a read can fail while Wi-Fi is busy, so prefer ADC1 pins (GPIO 1 to 10).
Every pin
Pads in order from the top, with the USB connector at the bottom. Numbers are GPIO numbers, which is what sketches use.
| Pad | Label | GPIO | Can do | Use it? |
|---|---|---|---|---|
| Left 1 | 3V3 | — | — | Power The 3.3 V supply. |
| Left 2 | 3V3 | — | — | Power The 3.3 V supply. |
| Left 3 | RST | — | — | Reset The reset pin. |
| Left 4 | 4 | 4 | ADC1_CH3, Touch TOUCH4, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 5 | 5 | 5 | ADC1_CH4, Touch TOUCH5, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 6 | 6 | 6 | ADC1_CH5, Touch TOUCH6, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 7 | 7 | 7 | ADC1_CH6, Touch TOUCH7, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 8 | 15 | 15 | ADC2_CH4, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 9 | 16 | 16 | ADC2_CH5, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 10 | 17 | 17 | ADC2_CH6, DAC1, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 11 | 18 | 18 | ADC2_CH7, DAC2, Deep-sleep wake | Care Drives the board's RGB LED. |
| Left 12 | 8 | 8 | ADC1_CH7, Touch TOUCH8, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 13 | 3 | 3 | ADC1_CH2, Touch TOUCH3, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 14 | 46 | 46 | Input only | Input only GPIO 46 can only read, and it is a strapping pin that must be low to enter download mode. |
| Left 15 | 9 | 9 | ADC1_CH8, Touch TOUCH9, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 16 | 10 | 10 | ADC1_CH9, Touch TOUCH10, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 17 | 11 | 11 | ADC2_CH0, Touch TOUCH11, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 18 | 12 | 12 | ADC2_CH1, Touch TOUCH12, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 19 | 13 | 13 | ADC2_CH2, Touch TOUCH13, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 20 | 14 | 14 | ADC2_CH3, Touch TOUCH14, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Left 21 | 5V | — | — | Power The 5 V supply from USB. |
| Left 22 | GND | — | — | Power Ground. |
| Right 1 | GND | — | — | Power Ground. |
| Right 2 | TX | 43 | UART0 TX | Serial Carries the serial console. Anything wired here fights with flashing and the bench. |
| Right 3 | RX | 44 | UART0 RX | Serial Carries the serial console. Anything wired here fights with flashing and the bench. |
| Right 4 | 1 | 1 | ADC1_CH0, Touch TOUCH1, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 5 | 2 | 2 | ADC1_CH1, Touch TOUCH2, Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 6 | 42 | 42 | JTAG MTMS | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 7 | 41 | 41 | JTAG MTDI | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 8 | 40 | 40 | JTAG MTDO | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 9 | 39 | 39 | JTAG MTCK | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 10 | 38 | 38 | — | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 11 | 37 | 37 | — | Care Used for octal flash or PSRAM on modules that have it. |
| Right 12 | 36 | 36 | — | Care Used for octal flash or PSRAM on modules that have it. |
| Right 13 | 35 | 35 | — | Care Used for octal flash or PSRAM on modules that have it. |
| Right 14 | 0 | 0 | Deep-sleep wake | Boot pin A strapping pin. Held low at reset, the chip enters download mode. |
| Right 15 | 45 | 45 | — | Boot pin A strapping pin that sets the flash voltage. |
| Right 16 | 34 | 34 | — | Care Used for octal flash or PSRAM on modules that have it. |
| Right 17 | 33 | 33 | — | Care Used for octal flash or PSRAM on modules that have it. |
| Right 18 | 21 | 21 | Deep-sleep wake | Safe A general-purpose pin with no boot, flash or USB duty. |
| Right 19 | 20 | 20 | ADC2_CH9, USB D+, Deep-sleep wake | Avoid The native USB D+ line. Using it breaks USB flashing and serial. |
| Right 20 | 19 | 19 | ADC2_CH8, USB D-, Deep-sleep wake | Avoid The native USB D- line. Using it breaks USB flashing and serial. |
| Right 21 | GND | — | — | Power Ground. |
| Right 22 | GND | — | — | Power Ground. |
The ESP32-S2 chip
| Feature | Value |
|---|---|
| CPU | Single-core Xtensa LX7, up to 240 MHz |
| Radio | Wi-Fi 4 (2.4 GHz). No Bluetooth |
| GPIOs | 43 (GPIO 46 is input only) |
| Analog in | 20 channels on two 13-bit ADCs |
| Touch | 14 channels |
| Analog out | 2 channels, 8-bit (GPIO 17 and 18) |
| USB | Native USB 1.1 OTG on GPIO 19 and 20 |
| SRAM | 320 KB |
Projects for this board
- Wi-Fi scanner List nearby networks with signal strength and channel every ten seconds. A quick radio health check.
- I2C bus scanner Probe every address on the I2C bus and report what answers. Run it before trusting any sensor wiring.
- ESP-NOW pair Two boards talk directly over the Wi-Fi radio, with no router. Each sends a counter and prints what the other sends.