ATMegaZero ESP32-S2
Raspberry Pi Zero-style ESP32-S2 board - ideal for Linux-style form factor with secure IoT power.
ATMegaZero ESP32-S2 Pinout
24 pins · 2.54 mm pitch| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | PD5 | strapping | - | |
| 2 | 1 | T1PWM | safe | touch | |
| 3 | 2 | T2PWM | safe | touch | |
| 4 | 3 | A5T3PWM | safe | adc · touch | |
| 5 | 4 | T4PWM | safe | touch | |
| 6 | 5 | T5PWM | safe | touch | |
| 7 | 6 | A4T6PWM | safe | adc · touch | |
| 8 | 7 | T7PWM | safe | touch | |
| 9 | 8 | SDAT8PWM | safe | touch · i2c | |
| 10 | 9 | SCLT9PWM | strapping | touch · i2c | |
| 11 | 10 | T10PWM | strapping | touch | |
| 12 | 11 | T11PWM | strapping | touch | |
| 13 | 12 | A3T12PWM | strapping | adc · touch | |
| 14 | 13 | A2T13PWM | strapping | adc · touch | |
| 15 | 14 | T14PWM | strapping | touch | |
| 16 | 17 | A0DAC1PWM | safe | adc · dac | |
| 17 | 18 | A1DAC2PWM | safe | adc · dac | |
| 18 | 35 | MOSIPWM | safe | spi | |
| 19 | 36 | SCKPWM | safe | spi | |
| 20 | 37 | MISOPWM | safe | spi | |
| 21 | 38 | SSPWM | safe | spi | |
| 22 | 40 | NEOPIXELPWM | strapping | - | |
| 23 | 43 | TXPWM | uart | uart | |
| 24 | 44 | RXPWM | uart | uart |
Start with these
16 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
8 pins · 3 things to knowPD5GPIO0 Bootstrapping pin; selects boot mode (SPI Boot vs UART Download). Strapping
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.
SCLGPIO9T10GPIO10T11GPIO11A3GPIO12A2GPIO13T14GPIO14 General-purpose SPI2 (FSPI) IO MUX pins Other
IO MUX pin of the general-purpose SPI2 (FSPI) bus, not of the in-package flash - that sits on GPIO26-32. The datasheet does not restrict it, so it is only taken if your board wires flash, an SD card or a display to FSPI.
- SCLGeneral-purpose SPI2 (FSPI) IO MUX pin - hold/data line (FSPIHD)
- T10General-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)
- T11General-purpose SPI2 (FSPI) IO MUX pin - data in (FSPID)
- A3General-purpose SPI2 (FSPI) IO MUX pin - clock (FSPICLK)
- A2General-purpose SPI2 (FSPI) IO MUX pin - data out (FSPIQ)
- T14General-purpose SPI2 (FSPI) IO MUX pin - write-protect/data line (FSPIWP)
NEOPIXELGPIO40 JTAG test data-out pin (MTDO); also GPIO40, supports CLK_OUT2. JTAG
Part of JTAG interface (TDO); should be avoided as GPIO if JTAG debugging is needed.
The ATMegaZero ESP32-S2 pinout brings out 24 GPIO pins at a 2.54 mm pitch - every one of them usable in your project.
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 6 ADC-capable pins for sensors and battery monitoring, 14 capacitive-touch inputs and 2 true DAC outputs.
If you want zero surprises, T1, T2, A5, T4 and 12 more are free of any such role - the safest first picks. 8 of the exposed pins carry boot-time or system duties on the ESP32-S2 (PD5, SCL, T10 and 5 more).
Getting started
flash your first firmware in ~2 minutesBoard: ESP32S2 Dev Module USB CDC On Boot: Enabled Flash Size: 16MB (128Mb) Flash Mode: QIO PSRAM: QSPI PSRAM Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS) Upload Speed: 921600
// toggle GPIO1 - wire an LED and resistor to it
void setup() {
pinMode(1, OUTPUT);
}
void loop() {
digitalWrite(1, HIGH); delay(500);
digitalWrite(1, LOW); delay(500);
}[env:atmegazero_esp32s2]
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_PSRAMesp32-s2-saola-1 - or type it after board =.esp32:
board: esp32-s2-saola-1
variant: esp32s2
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# blink - GPIO1
output:
- platform: gpio
pin: 1
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32-s2-saola-1 (same ids as PlatformIO).esptool.py --chip esp32s2 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32-S2 · 65 × 30 mm · vs other ESP32 chips →Dimensions
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 $24.99 - above the ~$20 typical for ESP32-S2 boards.
Onboard you'll find 8MB (QSPI) PSRAM, a microSD slot, an addressable RGB LED (GPIO40) and Reset buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S2 boards.
- Raspberry Pi Zero form factor with 40-pin GPIO header
- 30-pin FPC OLED display port for SSD1306/SH1106 displays (not included)
- 3D antenna for 2.4GHz Wi-Fi
- 4x onboard status LEDs
Where to buy
prices are typical street pricesResources
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