WiFiduinoV2
ESP32-C3 board with Arduino-like form factor - ideal for transitioning from AVR to RISC-V-based Wi-Fi projects.
WiFiduinoV2 Pinout
16 pins · 2.54 mm pitch| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | GPIO0 | adc · pwm · spi · i2c · uart | ||
| 2 | 1 | GPIO1 | adc · pwm · spi · i2c · uart | ||
| 3 | 2 | GPIO2 | adc · pwm · spi · i2c · uart | ||
| 4 | 3 | GPIO3 | adc · pwm · spi · i2c · uart | ||
| 5 | 4 | GPIO4 | adc · pwm · spi · i2c · uart | ||
| 6 | 5 | GPIO5 | adc · pwm · spi · i2c · uart | ||
| 7 | 6 | GPIO6 | pwm · spi · i2c · uart | ||
| 8 | 7 | GPIO7 | pwm · spi · i2c · uart | ||
| 9 | 8 | GPIO8 | pwm · spi · i2c · uart | ||
| 10 | 9 | GPIO9 | pwm · spi · i2c · uart | ||
| 11 | 10 | GPIO10 | pwm · spi · i2c · uart | ||
| 12 | 11 | GPIO11 | pwm · spi · i2c · uart | Requires eFuse burn (VDD_SPI) to use as a GPIO | |
| 13 | 18 | GPIO18 | pwm · spi · i2c · uart | ||
| 14 | 19 | GPIO19 | pwm · spi · i2c · uart | ||
| 15 | 20 | GPIO20 | pwm · spi · i2c · uart | ||
| 16 | 21 | GPIO21 | pwm · spi · i2c · uart |
Start with these
4 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
9 pins · 9 things to knowGPIO2 Strapping pin, but it does not select the boot mode - GPIO9 does. Espressif only recommend pulling it up against reset-time glitches. Floating by default. Strapping
A strapping pin: Espressif recommend an external pull-up against glitches at reset, so avoid heavy capacitive loads or a strong low drive here. It does not put the chip into download mode (that is GPIO9).
GPIO4 Bootstrapping pin; JTAG TMS; Flash data (FSPIHD in internal-flash models) JTAG
Used during boot; JTAG TMS for debugging; acts as Quad-SPI flash IO (hold data line) in internal-flash variants
GPIO5 Bootstrapping pin; JTAG TDI; Flash data (FSPIWP in internal-flash models) JTAG
Used during boot; JTAG TDI for debugging; acts as Quad-SPI flash IO (write-protect data line) in internal-flash variants
GPIO6 Bootstrapping pin; JTAG TCK; Flash clock (FSPICLK in internal-flash models) JTAG
Used during boot; JTAG TCK for debugging; provides flash clock in internal-flash variants
GPIO7 Bootstrapping pin; JTAG TDO; Flash data (FSPID in internal-flash models) JTAG
Used during boot; JTAG TDO for debugging; acts as Quad-SPI flash IO (data line) in internal-flash variants
GPIO8 Bootstrapping pin (needs HIGH at reset); also gates ROM boot message printing (UART_PRINT_CONTROL efuse) Strapping
Must be held high during reset (if low, UART flashing/boot may not work)
GPIO9 Bootstrapping pin; selects boot mode (HIGH = SPI flash boot, LOW = UART download) Strapping
Controls boot mode on reset (HIGH for normal flash boot, LOW enters serial download mode)
GPIO20 UART0 RXD (default serial input) UART
Used as UART0 receive (console/bootloader); repurposing may disable serial programming and debug logs
GPIO21 UART0 TXD (default serial output) UART
Used as UART0 transmit (console/bootloader); repurposing may disable serial console output and printing
Only if you know the tricks
3 pins · 3 things to knowGPIO11 Flash power supply pin (VDD_SPI) - can become GPIO11 if not used for flash power Flash
By default powers the SPI flash; only configurable as GPIO if the flash is powered externally (not recommended otherwise)
GPIO18 USB D- line (USB Serial/JTAG interface) USB
By default connected to on-chip USB Serial/JTAG controller; to use as GPIO it must be reconfigured from its USB function
GPIO19 USB D+ line (USB Serial/JTAG interface) USB
By default connected to on-chip USB Serial/JTAG controller; not available for GPIO use unless USB functionality is disabled or remapped
The WiFiduinoV2 pinout brings out 16 pins at a 2.54 mm pitch - 0 usable GPIO.
9 of the exposed pins carry boot-time or system duties on the ESP32-C3 (GPIO2, GPIO4, GPIO5 and 6 more) - check the guidance above before wiring anything to them. GPIO0, GPIO1, GPIO3 and GPIO10 are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32C3 Dev Module Flash Size: 4MB (32Mb) Flash Mode: QIO Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO8 - wire an LED and resistor to it
void setup() {
pinMode(8, OUTPUT);
}
void loop() {
digitalWrite(8, HIGH); delay(500);
digitalWrite(8, LOW); delay(500);
}[env:wifiduino32c3]
platform = espressif32
board = esp32-c3-devkitm-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32-c3-devkitm-1 - or type it after board =.esp32:
board: esp32-c3-devkitm-1
variant: esp32c3
framework:
type: esp-idf
# blink - GPIO8
output:
- platform: gpio
pin: 8
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32-c3-devkitm-1 (same ids as PlatformIO).esptool.py --chip esp32c3 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32-C3 · 68.6 × 53.4 mm · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32-C3 - a single-core RISC-V and the budget low-power pick.
Around the module: status LEDs (Power, User, TX, RX) and Reset/Boot buttons.
Resources
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