SparkFun ESP32 Thing Plus

Feather-compatible ESP32 board from SparkFun - ideal for professional-grade prototyping and STEM use.

Micro-USB
SparkFun ESP32 Thing Plus board
64.8 × 22.9 mm
ESP32
MCU
240MHz
clock
16MB
flash
520KB
SRAM
22· 13 ADC
GPIO
BLE 4.2+ WiFi
radio
On this page

Pinout

22 pins · 2.54 mm pitch
View:
SparkFun ESP32 Thing Plus pinout diagram
PinGPIOLabelsStatusCapabilitiesNotes
10T1strappingtouch
22T2PWMstrappingtouch
34A5T0PWMstrappingadc · touch
45SCKPWMstrappingspi
512A11T5PWMstrappingadc · touch
613LED_BUILTINA12T4PWMstrappingadc · touch
714A6T6PWMstrappingadc · touch
815A8T3PWMstrappingadc · touch
916RXPWMstrappinguart
1017TXPWMstrappinguart
1118MOSIPWMsafespi
1219MISOPWMsafespi
1322SCLPWMsafei2c
1423SDAPWMsafei2c
1525A1DAC1PWMsafeadc · dac
1626A0DAC2PWMsafeadc · dac
1727A10T7PWMsafeadc · touch
1832A7T9PWMsafeadc · touch
1933SSA9T8PWMsafeadc · touch · spi
2034A2strappingadc
2136A4strappingadc
2239A3strappingadc

Start with these

9 pins with no boot or system involvement
MOSIPWMMISOPWMSCLPWMSDAPWMA1DAC1A0DAC2A10T7A7T9SSA9

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
T1GPIO0Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.Strapping
T2GPIO2If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.Strapping
A5GPIO4Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).Strapping
SCKGPIO5Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.Strapping
A11MTDI (GPIO12)Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.Strapping
LED_BUILTINMTCK (GPIO13)Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.Other
A6MTMS (GPIO14)Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.Other
A8MTDO (GPIO15)Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.Strapping
A2GPIO34Cannot be used as output (no drive capability); only suitable for analog/digital input.Other
A4GPIO36 (SENSOR_VP)Cannot be used as output; only suitable for input (e.g., analog read).Other
A3GPIO39 (SENSOR_VN)Cannot be used as output; only suitable for input.Other

Only if you know the tricks

wired to flash or USB - expect a fight
PinLabelWhat to knowRole
RXGPIO16Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.Flash
TXGPIO17Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.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 The SparkFun ESP32 Thing Plus pinout brings out 22 GPIO pins at a 2.54 mm pitch - every one of them usable in your project. For peripherals, I²C is mapped to…

The SparkFun ESP32 Thing Plus pinout brings out 22 GPIO pins at a 2.54 mm pitch - every one of them usable in your project.

For peripherals, I²C is mapped to SDA on GPIO23 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO17 and GPIO16 cover serial logging and flashing.

On the analog side there are 13 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.

If you want zero surprises, MOSI, MISO, SCL, SDA and 5 more are free of any such role - the safest first picks. 11 of the exposed pins carry boot-time or system duties on the ESP32 (T1, T2, A5 and 8 more).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Serial chip: CP2104. Not detected? Hold BOOT while plugging in.
2
Flash with your tool
Arduino IDE, PlatformIO, ESPHome or esptool - copy the settings on the right.
3
Verify it runs
The blink example uses GPIO18 - swap for your board's LED pin if different.
Tools → Board settings Copy
Board:            Esp32 Thing Plus
Flash Size:       16MB · DIO
Upload Speed:     921600

// blink
pinMode(18, OUTPUT);
digitalWrite(18, LOW);   // on (often inverted)
platformio.ini Copy
[env:esp32thing_plus]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
device.yaml Copy
esp32:
  board: esp32dev
  variant: esp32thing_plus
  framework:
    type: esp-idf

# blink - GPIO18
output:
  - platform: gpio
    pin: 18
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
shell Copy
esptool.py --chip esp32 --port /dev/ttyACM0 \
  write_flash 0x0 firmware.bin
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32 · 64.8 × 22.9 mm
Compute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 16MB
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
22 · 13
UART · I²C · SPI
3 · 2 · 4
PWM
16 channels
Power
USB
Micro-USB
Serial
CP2104
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
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 Thing Plus 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 1.25 MB with 320 KB available for data.

About this board

At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.

Expect to pay about $24.95 - above the ~$20 typical for ESP32 boards.

Onboard you'll find a microSD slot, a Qwiic connector, battery charging (MCP73831) via JST-PH 2.0 and Reset/Boot buttons.

Where to buy

prices are typical street prices
SparkFun ESP32 Thing Plus
SparkFun ESP32 Thing Plus
$24.95per unit, typical

Resources

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