Espressif ESP32-PICO-KIT-1

Small ESP32 dev board using PICO-D4 SiP - great for tight-space applications and integration.

Micro-USB
Espressif ESP32-PICO-KIT-1 board
47 × 20.3 mm
ESP32
MCU
240MHz
clock
4MB
flash
520KB
SRAM
26· 16 ADC
GPIO
BLE 4.2+ WiFi
radio
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Espressif ESP32-PICO-KIT-1 Pinout

26 pins · 2.54 mm pitch
Espressif ESP32-PICO-KIT-1 pinout diagram
PinGPIOLabelsStatusCapabilitiesNotes
10A11T1PWMstrappingadc · touch
21TXPWMuartuart
32A12T2PWMstrappingadc · touch
43RXPWMuartuart
54A10T0PWMsafeadc · touch
65PWMstrapping-
712A15T5PWMstrappingadc · touch
813A14T4PWMstrappingadc · touch
914A16T6PWMstrappingadc · touch
1015A13T3PWMstrappingadc · touch
1116PWMstrapping-
1217PWMstrapping-
1318PWMsafe-
1419PWMsafe-
1521PWMsafe-
1622PWMsafe-
1723PWMsafe-
1825A18DAC1PWMsafeadc · dac
1926A19DAC2PWMsafeadc · dac
2027A17T7PWMsafeadc · touch
2132A4T9PWMsafeadc · touch
2233A5T8PWMsafeadc · touch
2334A6strappingadc
2435A7strappingadc
2536A0strappingadc
2639A3strappingadc
26 GPIOs broken out 11 free · 15 need care · 0 to avoid

Start with these

11 pins with no boot or system involvement
A10GPIO4PWMGPIO18PWMGPIO19PWMGPIO21PWMGPIO22PWMGPIO23A18GPIO25A19GPIO26A17GPIO27A4GPIO32A5GPIO33

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

15 pins · 13 things to know
A11GPIO0 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.

A12GPIO2 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.

PWMGPIO5 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.

A15GPIO12 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.

A14GPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG

Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.

A16GPIO14 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.

A13GPIO15 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.

PWMGPIO16PWMGPIO17 PSRAM chip select and clock on WROVER-class modules; in-package flash lines on ESP32-U4WDH. Both also carry UART2 PSRAM

Wired to the memory die on PSRAM-equipped modules (WROVER, PICO-V3-02) and on in-package-memory chip variants (U4WDH, D0WDRH2-V3); an ordinary GPIO on a plain WROOM-32.

  • PWMPSRAM CS# on WROVER-class modules and on ESP32-D0WDRH2-V3; in-package flash CS# on ESP32-U4WDH. Also UART2 RX.
  • PWMPSRAM clock on WROVER-class modules; in-package flash IO1/DO on ESP32-U4WDH. Also UART2 TX.
A6GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other

Cannot be used as output (no drive capability); only suitable for analog/digital input.

A7GPIO35A3GPIO39 Input-only GPIOs with ADC1 channels - no output driver Other

Cannot be used as output; only suitable for input.

  • A7Input-only GPIO (no output driver); ADC1 channel 7.
  • A3Input-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
A0GPIO36 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).

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.

The Espressif ESP32-PICO-KIT-1 pinout brings out 26 GPIO pins at a 2.54 mm pitch - every one of them usable in your project.

For peripherals, TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.

On the analog side there are 16 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.

If you want zero surprises, A10, PWM, PWM, PWM and 7 more are free of any such role - the safest first picks. 15 of the exposed pins carry boot-time or system duties on the ESP32 (A11, TX, A12 and 12 more).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Install your USB-serial driver (CH340 / CP210x) 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
GPIO4 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
Set these in Tools · leave everything else at default
Arduino IDE 2.x - Tools Copy
Board: "ESP32 Dev Module"▸
Flash Size: "4MB (32Mb)"▸
Flash Mode: "DIO"▸
Partition Scheme: "Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)" (default)▸
Upload Speed: "921600"▸
▸ every other Tools option - leave at default
Board: ESP32 Dev Module
Flash Size: 4MB (32Mb)
Flash Mode: DIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32 Dev Module
blink.ino Copy
// 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);
}
board to selectesp32dev⧉ copy
platformio.ini Copy
[env:esp32-pico-kit-1]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
Find it: PlatformIO Home ▸ Boards, search esp32dev - or type it after board =.
board to selectesp32dev⧉ copy
device.yaml Copy
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_out
Find it: search ESPHome's board list for esp32dev (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 esp32 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x1000 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1966080 B · data 327680 B · DIO

Specifications

ESP32 · 47 × 20.3 mm · vs other ESP32 chips →
Compute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 4MB
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
26 · 16
UART · I²C · SPI
3 · 2 · 2
PWM
16 channels
Power
USB
Micro-USB
Serial
CP2102N
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.88 MB · 320 KB

Dimensions

20.3 mm47 mm
47 × 20.3 mm · pin pitch 2.54 mm
The Espressif ESP32-PICO-KIT-1 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 1.88 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 $10.00 - less than the ~$20 most ESP32 boards go for.

Onboard you'll find EN/Boot buttons.

Where to buy

prices are typical street prices
Espressif ESP32-PICO-KIT-1
Espressif ESP32-PICO-KIT-1
$10.00per unit, typical
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