SparkFun ESP32 MicroMod
ESP32 processor board for the MicroMod ecosystem - ideal for modular embedded development.
SparkFun ESP32 MicroMod Pinout
25 pins| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | T1 | strapping | touch | |
| 2 | 1 | TXWIRE1_PIN_DEFINEDPWM | uart | uart | |
| 3 | 2 | T2LED_BUILTINPWM | strapping | touch | |
| 4 | 3 | RXPWM | uart | uart | |
| 5 | 4 | I2C_INTT0PWM | safe | touch | |
| 6 | 5 | SSPWM | strapping | spi | |
| 7 | 12 | PWM1T5PWM | strapping | touch | |
| 8 | 13 | PWM0T4PWM | strapping | touch | |
| 9 | 14 | D0T6PWM | strapping | touch | |
| 10 | 15 | G0T3PWM | strapping | touch | |
| 11 | 16 | RX1G4AUD_INPWM | safe | - | |
| 12 | 17 | TX1G3AUD_OUTPWM | safe | - | |
| 13 | 18 | SCKPWM | safe | spi | |
| 14 | 19 | MISOPWM | safe | spi | |
| 15 | 21 | SDAPWM | safe | i2c | |
| 16 | 22 | SCLPWM | safe | i2c | |
| 17 | 23 | MOSIPWM | safe | spi | |
| 18 | 25 | SCL1G1AUD_LRCLKDAC1PWM | safe | dac | |
| 19 | 26 | SDA1G2AUD_BCLKDAC2PWM | safe | dac | |
| 20 | 27 | D1T7PWM | safe | touch | |
| 21 | 32 | G5T9PWM | safe | touch | |
| 22 | 33 | G6T8PWM | safe | touch | |
| 23 | 34 | A0 | strapping | adc | |
| 24 | 35 | A1 | strapping | adc | |
| 25 | 39 | BATT_VIN | strapping | - |
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
12 pins · 11 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.
TXGPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
T2GPIO2 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.
RXGPIO3 Default UART0 RX pin for USB-serial programming (console input). UART
Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.
SSGPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping
Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.
PWM1GPIO12 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.
PWM0GPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
D0GPIO14 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.
G0GPIO15 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.
A0GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other
Cannot be used as output (no drive capability); only suitable for analog/digital input.
A1GPIO35BATT_VINGPIO39 Input-only GPIOs with ADC1 channels - no output driver Other
Cannot be used as output; only suitable for input.
- A1Input-only GPIO (no output driver); ADC1 channel 7.
- BATT_VINInput-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
All 25 pins on the SparkFun ESP32 MicroMod are usable GPIO.
Peripheral wiring is straightforward: 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 GPIO1 and GPIO3 cover serial logging and flashing.
Beyond plain digital I/O you get 2 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.
12 of the exposed pins carry boot-time or system duties on the ESP32 (T1, TX, T2 and 9 more) - check the guidance above before wiring anything to them. I2C_INT, RX1, TX1, SCK and 9 more are free of any such role - the safest first picks.
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:esp32micromod]
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 · 22 × 22 mm · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
The $19.95 price tag is typical for an ESP32 board.
Around the module: status LEDs (Status (GPIO2)).
- No onboard USB - plugs into a MicroMod carrier board via the M.2 (E-key) edge connector
- MicroMod M.2 form factor - the ESP32 is broken out through the edge connector, not 0.1" headers
Where to buy
prices are typical street pricesResources
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