SparkFun ESP32 Thing Plus C
USB-C version of the Thing Plus ESP32 board - great for modern prototyping with Feather-compatible layout.
SparkFun ESP32 Thing Plus C Pinout
23 pins · 2.54 mm pitch| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | T1 | strapping | touch | |
| 2 | 2 | RGB_BUILTINT2PWM | strapping | touch | |
| 3 | 4 | T0PWM | safe | touch | |
| 4 | 12 | A11T5PWM | strapping | adc · touch | |
| 5 | 13 | LED_BUILTINA12T4PWM | strapping | adc · touch | |
| 6 | 14 | A6T6PWM | strapping | adc · touch | |
| 7 | 15 | SSA8T3PWM | strapping | adc · touch · spi | |
| 8 | 16 | RXPWM | uart | uart | |
| 9 | 17 | TXPWM | uart | uart | |
| 10 | 18 | SCKPWM | safe | spi | |
| 11 | 19 | MISOPWM | safe | spi | |
| 12 | 21 | SDAPWM | safe | i2c | |
| 13 | 22 | SCLPWM | safe | i2c | |
| 14 | 23 | MOSIPWM | safe | spi | |
| 15 | 25 | A1DAC1PWM | safe | adc · dac | |
| 16 | 26 | A0DAC2PWM | safe | adc · dac | |
| 17 | 27 | A10T7PWM | safe | adc · touch | |
| 18 | 32 | A7T9PWM | safe | adc · touch | |
| 19 | 33 | A9T8PWM | safe | adc · touch | |
| 20 | 34 | A2 | strapping | adc | |
| 21 | 35 | A5 | strapping | adc | |
| 22 | 36 | A4 | strapping | adc | |
| 23 | 39 | A3 | strapping | adc |
Start with these
13 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
10 pins · 9 things to knowT1GPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping
Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.
RGB_BUILTINGPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping
If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.
A11GPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping
Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.
LED_BUILTINGPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
A6GPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG
Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.
SSGPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
A2GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other
Cannot be used as output (no drive capability); only suitable for analog/digital input.
A5GPIO35A3GPIO39 Input-only GPIOs with ADC1 channels - no output driver Other
Cannot be used as output; only suitable for input.
- A5Input-only GPIO (no output driver); ADC1 channel 7.
- A3Input-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
A4GPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other
Cannot be used as output; only suitable for input (e.g., analog read).
The SparkFun ESP32 Thing Plus C pinout brings out 23 GPIO pins at a 2.54 mm pitch - every one of them usable in your project.
For peripherals, I²C is mapped to SDA on GPIO21 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, T0, RX, TX, SCK and 9 more are free of any such role - the safest first picks. 10 of the exposed pins carry boot-time or system duties on the ESP32 (T1, RGB_BUILTIN, A11 and 7 more).
Getting started
flash your first firmware in ~2 minutesBoard: ESP32 Dev Module Flash Size: 16MB (128Mb) Flash Mode: DIO Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS) Upload Speed: 921600
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
pinMode(4, OUTPUT);
}
void loop() {
digitalWrite(4, HIGH); delay(500);
digitalWrite(4, LOW); delay(500);
}[env:esp32thing_plus_c]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
framework:
type: esp-idf
# blink - GPIO4
output:
- platform: gpio
pin: 4
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32 · 58.4 × 22.9 mm · vs other ESP32 chips →Dimensions
About this board
At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
Expect to pay about $29.95 - above the ~$20 typical for ESP32 boards.
Onboard you'll find a microSD slot, a Qwiic connector, an addressable RGB LED (GPIO2), a battery fuel gauge (MAX17048), battery charging (MCP73831) via JST-PH 2.0, status LEDs (Power, Charge, Status) and Reset/Boot buttons.
Where to buy
prices are typical street pricesResources
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