SparkFun ESP32-S2 Thing Plus

Feather-compatible ESP32-S2 board with USB and LiPo - ideal for secure IoT and hardware prototyping.

USB-C
SparkFun ESP32-S2 Thing Plus board
64.8 × 22.9 mm
ESP32-S2
MCU
240MHz
clock
4MB
flash
320KB
SRAM
28· 15 ADC
GPIO
Wi-Fi
radio
On this page

Pinout

28 pins · 2.54 mm pitch
View:
PinGPIOLabelsStatusCapabilitiesNotes
11SDAT1PWMsafetouch · i2c
22SCLT2PWMsafetouch · i2c
33T3PWMsafetouch
44T4PWMsafetouch
55A5T5PWMsafeadc · touch
66T6PWMsafetouch
77A4A6T7PWMsafeadc · touch
88A7T8PWMsafeadc · touch
99A3A8T9PWMstrappingadc · touch
1010A9T10PWMstrappingadc · touch
1111A10T11PWMstrappingadc · touch
1212A11T12PWMstrappingadc · touch
1313LED_BUILTINA12T13PWMstrappingadc · touch
1414A2A13T14PWMstrappingadc · touch
1515A14PWMstrappingadc
1616A15PWMstrappingadc
1717A0A16DAC1PWMsafeadc · dac
1818A1A17DAC2PWMsafeadc · dac
1919A18PWMuartadc
2020A19PWMuartadc
2133RX1PWMstrapping-
2234TX1PWMstrapping-
2335MOSIPWMstrappingspi
2436SCKPWMstrappingspi
2537MISOPWMstrappingspi
2642SSPWMstrappingspi
2743TXPWMuartuart
2844RXPWMuartuart

Start with these

12 pins with no boot or system involvement
SDAT1SCLT2T3PWMT4PWMA5T5T6PWMA4A6A7T8A0A16A1A17TXPWMRXPWM

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
PinLabelWhat to knowRole
A14XTAL_32K_PIf an external 32 kHz crystal is used for RTC, this pin is dedicated to the crystal and cannot be used as GPIO.Other
A15XTAL_32K_NIf using an external 32 kHz crystal, this pin is connected to the crystal and should not be used as general I/O.Other
SSMTMSJTAG TMS pin; should not be repurposed if JTAG debugging or programming via JTAG is required.Other

Only if you know the tricks

wired to flash or USB - expect a fight
PinLabelWhat to knowRole
A3FSPIHDTypically used as flash/PSRAM IO line in certain configurations; avoid using as GPIO if flash or PSRAM is present.Flash
A9FSPICS0Often used as flash chip select in some designs; not available for GPIO when controlling flash.Flash
A10FSPIDUsed for flash data transfer in certain configurations; should be avoided for general use if flash is connected.Flash
A11FSPICLKUsed as flash clock line in some boards; not free for GPIO if driving flash.Flash
LED_BUILTINFSPIQUsed for flash data output in certain configurations; avoid using as GPIO if connected to flash.Flash
A2FSPIWPUsed as flash write-protect/data line on some modules; not recommended for other usage.Flash
A18USB_D-Used for USB communication; using this pin as general GPIO can interfere with USB functionality.USB
A19USB_D+Dedicated to USB interface; repurposing as GPIO may disrupt USB connectivity.USB
RX1SPIHDConnected to SPI flash (hold/data line); not available for general-purpose use.Flash
TX1SPIWPConnected to SPI flash (write-protect/data line); not recommended for other use.Flash
MOSIFSPIDUsed by internal flash/PSRAM on some ESP32-S2 variants; avoid using as GPIO to prevent conflicts.Flash
SCKFSPICLKMay be connected to internal flash or used for high-speed SPI; not intended for general GPIO use.Flash
MISOFSPIQUsed for internal flash/PSRAM data in some models; should not be repurposed for GPIO.Flash
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 All 28 pins on the SparkFun ESP32-S2 Thing Plus are usable GPIO, spaced at the standard 2.54 mm pitch. Peripheral wiring is straightforward: I²C is mapped to…

All 28 pins on the SparkFun ESP32-S2 Thing Plus are usable GPIO, spaced at the standard 2.54 mm pitch.

Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO1 and SCL on GPIO2; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.

Beyond plain digital I/O you get 15 ADC-capable pins for sensors and battery monitoring, 14 capacitive-touch inputs and 2 true DAC outputs.

3 of the exposed pins carry boot-time or system duties on the ESP32-S2 (A14, A15 and SS) - check the guidance above before wiring anything to them. SDA, SCL, T3, T4 and 8 more are free of any such role - the safest first picks.

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Uses a CP2102 bridge - install the CP210x driver if no port appears. 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 GPIO1 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"
Flash Size: "4MB (32Mb)"
Flash Mode: "QIO"
Partition Scheme: "Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS)" (default)
Upload Speed: "921600"
▸ every other Tools option — leave at default
Board: ESP32S2 Dev Module
Flash Size: 4MB (32Mb)
Flash Mode: QIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32S2 Dev Module
blink.ino Copy
// blink the onboard LED
void setup() {
  pinMode(1, OUTPUT);
}
void loop() {
  digitalWrite(1, HIGH); delay(500);
  digitalWrite(1, LOW);  delay(500);
}
board to selectesp32-s2-saola-1⧉ copy
platformio.ini Copy
[env:sparkfun_esp32s2_thing_plus]
platform = espressif32
board = esp32-s2-saola-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
Find it: PlatformIO Home ▸ Boards, search esp32-s2-saola-1 — or type it after board =.
board to selectesp32-s2-saola-1⧉ copy
device.yaml Copy
esp32:
  board: esp32-s2-saola-1
  variant: esp32s2thing_plus
  framework:
    type: esp-idf

# blink - GPIO1
output:
  - platform: gpio
    pin: 1
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find 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.
terminal Copy
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 1310720 B · data 327680 B · QIO

Specifications

ESP32-S2 · 64.8 × 22.9 mm
Compute
MCU
ESP32-S2
Clock
240 MHz
SRAM · Flash
320 KB · 4MB
Radio
Wi-Fi
802.11 b/g/n 2.4 GHz
Bluetooth
-
Antenna
PCB
I/O
GPIO · ADC
28 · 15
UART · I²C · SPI
2 · 1 · 4
PWM
8 channels
Power
USB
USB-C
Serial
CP2102
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
QIO · QIO
Sketch · Data
1.25 MB · 320 KB
22.9 mm64.8 mm
64.8 × 22.9 mm · pin pitch 2.54 mm
The SparkFun ESP32-S2 Thing Plus uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is QIO with QIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

Inside sits the ESP32-S2 - a single-core Xtensa with native USB-OTG and no Bluetooth.

At $24.50 it's on the expensive side for an ESP32-S2 board - most land around $20.

Around the module: a Qwiic connector, battery charging (MCP73831) via JST-PH 2.0, status LEDs (Status (IO18), Charge) and Reset/Boot (IO0) buttons.

Where to buy

prices are typical street prices
SparkFun ESP32-S2 Thing Plus
SparkFun ESP32-S2 Thing Plus
$24.50per unit, typical

Resources

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