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Espressif ESP32-S2-DevKitC-1
Full-featured official ESP32-S2 dev board - ideal for development with USB, Wi-Fi, and secure features.
62.74 × 25.4 mm
ESP32-S2
MCU
240MHz
clock
8MB
flash
320KB
SRAM
36· 20 ADC
GPIO
Wi-Fi
radio
Pinout
44 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | - | 3V33.3V | power | - | 3.3V regulated output |
| 2 | - | 3V33.3V | power | - | 3.3V regulated output |
| 3 | - | RSTEN | control | - | Chip reset (active low) |
| 4 | 4 | IO4A3T4 | safe | adc · touch · pwm | ADC1_CH3; touch T4; RTC |
| 5 | 5 | IO5A4T5 | safe | adc · touch · pwm | ADC1_CH4; touch T5; RTC |
| 6 | 6 | IO6A5T6 | safe | adc · touch · pwm | ADC1_CH5; touch T6; RTC |
| 7 | 7 | IO7A6T7 | safe | adc · touch · pwm | ADC1_CH6; touch T7; RTC |
| 8 | 15 | IO15A14 | strapping | adc · uart · pwm | ADC2_CH4; U0RTS; XTAL_32K_P; RTC |
| 9 | 16 | IO16A15 | strapping | adc · uart · pwm | ADC2_CH5; U0CTS; XTAL_32K_N; RTC |
| 10 | 17 | IO17A16DAC1 | uart | adc · dac · uart · pwm | DAC1; ADC2_CH6; U1 TX; RTC |
| 11 | 18 | IO18A17DAC2 | uart | adc · dac · uart · pwm | DAC2; onboard RGB LED; ADC2_CH7; U1 RX; RTC |
| 12 | 8 | IO8A7T8SDA | safe | adc · touch · i2c · pwm | ADC1_CH7; touch T8; default I2C SDA; RTC |
| 13 | 3 | IO3A2T3 | safe | adc · touch · pwm | ADC1_CH2; touch T3; RTC |
| 14 | 46 | IO46 | strapping | - | Input only; boot log output |
| 15 | 9 | IO9A8T9SCL | strapping | adc · touch · i2c · spi · pwm | ADC1_CH8; touch T9; default I2C SCL; FSPIHD; RTC |
| 16 | 10 | IO10A9T10 | strapping | adc · touch · spi · pwm | ADC1_CH9; touch T10; FSPICS0; RTC |
| 17 | 11 | IO11A10T11 | strapping | adc · touch · spi · pwm | ADC2_CH0; touch T11; FSPID (MOSI); RTC |
| 18 | 12 | IO12A11T12 | strapping | adc · touch · spi · pwm | ADC2_CH1; touch T12; FSPICLK (SCK); RTC |
| 19 | 13 | IO13A12T13 | strapping | adc · touch · spi · pwm | ADC2_CH2; touch T13; FSPIQ (MISO); RTC |
| 20 | 14 | IO14A13T14 | strapping | adc · touch · spi · pwm | ADC2_CH3; touch T14; FSPIWP; RTC |
| 21 | - | 5V | power | - | 5V input (from USB) / output |
| 22 | - | GND | ground | - | Ground |
| 23 | - | GND | ground | - | Ground |
| 24 | 43 | IO43TX | uart | uart · pwm | UART0 TX |
| 25 | 44 | IO44RX | uart | uart · pwm | UART0 RX |
| 26 | 1 | IO1A0T1 | safe | adc · touch · pwm | ADC1_CH0; touch T1; RTC |
| 27 | 2 | IO2A1T2 | safe | adc · touch · pwm | ADC1_CH1; touch T2; RTC |
| 28 | 42 | IO42 | strapping | pwm | JTAG MTMS |
| 29 | 41 | IO41 | strapping | pwm | JTAG MTDI |
| 30 | 40 | IO40 | strapping | pwm | JTAG MTDO |
| 31 | 39 | IO39 | strapping | pwm | JTAG MTCK |
| 32 | 38 | IO38 | strapping | spi · pwm | FSPIWP |
| 33 | 37 | IO37MISO | strapping | spi · pwm | Default SPI MISO (FSPIQ) |
| 34 | 36 | IO36SCK | strapping | spi · pwm | Default SPI SCK (FSPICLK) |
| 35 | 35 | IO35MOSI | strapping | spi · pwm | Default SPI MOSI (FSPID) |
| 36 | 0 | IO0BOOT | strapping | pwm | BOOT button; RTC |
| 37 | 45 | IO45 | strapping | pwm | General-purpose GPIO |
| 38 | 34 | IO34SS | strapping | spi · pwm | Default SPI SS (FSPICS0) |
| 39 | 33 | IO33 | strapping | spi · pwm | FSPIHD |
| 40 | 21 | IO21 | safe | pwm | General-purpose GPIO; RTC |
| 41 | 20 | IO20A19 | uart | adc · uart · pwm | USB D+ (native USB); ADC2_CH9; U1CTS; RTC |
| 42 | 19 | IO19A18 | uart | adc · uart · pwm | USB D- (native USB); ADC2_CH8; U1RTS; RTC |
| 43 | - | GND | ground | - | Ground |
| 44 | - | GND | ground | - | Ground |
Start with these
13 pins with no boot or system involvementIO4A3IO5A4IO6A5IO7A6IO17A16IO18A17IO8A7IO3A2IO43TXIO44RXIO1A0IO2A1IO21
Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
sampled at boot or shared with debug/serial| Pin | Label | What to know | Role |
|---|---|---|---|
| IO15 | XTAL_32K_P | If an external 32 kHz crystal is used for RTC, this pin is dedicated to the crystal and cannot be used as GPIO. | Other |
| IO16 | XTAL_32K_N | If using an external 32 kHz crystal, this pin is connected to the crystal and should not be used as general I/O. | Other |
| IO46 | GPIO46 | If pulled high during boot, it can disable bootloader log output (depending on eFuse settings). Cannot drive output (input-only pin). | Strapping |
| IO42 | MTMS | JTAG TMS pin; should not be repurposed if JTAG debugging or programming via JTAG is required. | Other |
| IO41 | MTDI | Part of JTAG interface (TDI); avoid using as GPIO to retain ability for JTAG debug. | Other |
| IO40 | MTDO | Part of JTAG interface (TDO); should be avoided as GPIO if JTAG debugging is needed. | Other |
| IO39 | MTCK | Used for JTAG debugging interface; using this pin for other purposes will disable JTAG clock input. | Other |
| IO0 | GPIO0 | Must be pulled high for normal boot; pulling low at reset enters bootloader (download mode). Also serves as SPI flash data-in (SPID) line when using external flash memory. | Strapping |
| IO45 | GPIO45 | Must be set correctly at boot (usually low for 3.3 V); improper level can cause boot failure or flash malfunction. | Strapping |
Only if you know the tricks
wired to flash or USB - expect a fight| Pin | Label | What to know | Role |
|---|---|---|---|
| IO9 | FSPIHD | Typically used as flash/PSRAM IO line in certain configurations; avoid using as GPIO if flash or PSRAM is present. | Flash |
| IO10 | FSPICS0 | Often used as flash chip select in some designs; not available for GPIO when controlling flash. | Flash |
| IO11 | FSPID | Used for flash data transfer in certain configurations; should be avoided for general use if flash is connected. | Flash |
| IO12 | FSPICLK | Used as flash clock line in some boards; not free for GPIO if driving flash. | Flash |
| IO13 | FSPIQ | Used for flash data output in certain configurations; avoid using as GPIO if connected to flash. | Flash |
| IO14 | FSPIWP | Used as flash write-protect/data line on some modules; not recommended for other usage. | Flash |
| IO38 | FSPIWP | Reserved for flash/PSRAM in ESP32-S2 modules with internal memory; not recommended for general I/O. | Flash |
| IO37 | FSPIQ | Used for internal flash/PSRAM data in some models; should not be repurposed for GPIO. | Flash |
| IO36 | FSPICLK | May be connected to internal flash or used for high-speed SPI; not intended for general GPIO use. | Flash |
| IO35 | FSPID | Used by internal flash/PSRAM on some ESP32-S2 variants; avoid using as GPIO to prevent conflicts. | Flash |
| IO34 | SPIWP | Connected to SPI flash (write-protect/data line); not recommended for other use. | Flash |
| IO33 | SPIHD | Connected to SPI flash (hold/data line); not available for general-purpose use. | Flash |
| IO20 | USB_D+ | Dedicated to USB interface; repurposing as GPIO may disrupt USB connectivity. | USB |
| IO19 | USB_D- | Used for USB communication; using this pin as general GPIO can interfere with USB functionality. | USB |
These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.
Pinout notes The Espressif ESP32-S2-DevKitC-1 pinout brings out 44 pins at a 2.54 mm pitch - 36 usable GPIO alongside the 3V3 , 5V and GND power rails. For peripherals, I²C…
The Espressif ESP32-S2-DevKitC-1 pinout brings out 44 pins at a 2.54 mm pitch - 36 usable GPIO alongside the 3V3, 5V and GND power rails.
For peripherals, I²C is mapped to SDA on GPIO8 and SCL on GPIO9; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.
On the analog side there are 20 ADC-capable pins for sensors and battery monitoring, PWM on 35 pins, 14 capacitive-touch inputs and 2 true DAC outputs.
If you want zero surprises, IO4, IO5, IO6, IO7 and 9 more are free of any such role - the safest first picks. 9 of the exposed pins carry boot-time or system duties on the ESP32-S2 (IO15, IO16, IO46 and 6 more).
Getting started
flash your first firmware in ~2 minutes1
Connect over USB
Native USB - shows up as a port right away, no driver needed. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
The onboard LED on GPIO4 blinks - swap the pin if your board's LED differs.
Set these in Tools · leave everything else at default
Arduino IDE 2.x — Tools Copy
Board: "ESP32S2 Dev Module"▸
USB CDC On Boot: "Enabled"▸
Flash Size: "8MB (64Mb)"▸
Flash Mode: "DIO"▸
PSRAM: "QSPI PSRAM"▸
Partition Scheme: "8M with spiffs (3MB APP / 1.5MB SPIFFS)" (default)▸
Upload Speed: "921600"▸
▸ every other Tools option — leave at default
Board: ESP32S2 Dev Module USB CDC On Boot: Enabled Flash Size: 8MB (64Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: 8M with spiffs (3MB APP / 1.5MB SPIFFS) Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32S2 Dev Module
// blink the onboard LED
void setup() {
pinMode(4, OUTPUT);
}
void loop() {
digitalWrite(4, HIGH); delay(500);
digitalWrite(4, LOW); delay(500);
}board to selectesp32-s2-saola-1⧉ copy
[env:esp32-s2-devkitc-1]
platform = espressif32
board = esp32-s2-saola-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAMFind it: PlatformIO Home ▸ Boards, search
esp32-s2-saola-1 — or type it after board =.board to selectesp32-s2-saola-1⧉ copy
esp32:
board: esp32-s2-saola-1
variant: esp32_s2_devkitc_1
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# blink - GPIO4
output:
- platform: gpio
pin: 4
id: led_out
light:
- platform: binary
name: "LED"
output: led_outFind it: search ESPHome's board list for
esp32-s2-saola-1 (same ids as PlatformIO).esptool doesn't pick board settings — a prebuilt .bin already has them baked in. This is just the raw flash command.
esptool.py --chip esp32s2 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Build details: sketch space 2097152 B · data 327680 B · DIO
Specifications
ESP32-S2 · 62.74 × 25.4 mmCompute
MCU
ESP32-S2
Clock
240 MHz
SRAM · Flash
320 KB · 8MB · 2MB (QSPI) PSRAM
Radio
Wi-Fi
802.11 b/g/n 2.4 GHz
Bluetooth
-
Antenna
PCB
I/O
GPIO · ADC
36 · 20
UART · I²C · SPI
2 · 1 · 4
PWM
8 channels
Power
USB
Micro-USB (UART) · Micro-USB (native)
Serial
-
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
2 MB · 320 KB
62.74 × 25.4 mm · pin pitch 2.54 mm
The Espressif ESP32-S2-DevKitC-1 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 2 MB with 320 KB available for data.
About this board
At its core is the ESP32-S2 - a single-core Xtensa with native USB-OTG and no Bluetooth.
Expect to pay about $8.00 - less than the ~$20 most ESP32-S2 boards go for.
36 GPIO are broken out - more than most ESP32-S2 boards, so the pin budget is rarely the constraint.
Onboard you'll find 2MB (QSPI) PSRAM, an addressable RGB LED (GPIO18) and Boot/Reset buttons.
- 2 MB PSRAM (ESP32-S2-SOLO-2 module, N8R2 variant)
- Sold in 8 MB and 4 MB flash variants
- External u.FL antenna connector on -U variants
Where to buy
prices are typical street pricesAs an Amazon Associate, ESPboards earns from qualifying purchases.
Resources
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