Flipper Zero GPIO Pinout and Hardware Expansion: UART, I2C, ADC, 1-Wire, and Sensor Wiring
The Flipper Zero has an 18-pin GPIO header on the top edge, exposing UART, I2C, SPI, ADC, 1-Wire, and power rails from the STM32WB55 microcontroller.
Pin 1 Location
Hold the Flipper with the screen facing you, GPIO header at top. Pin 1 is on the left. See the full interactive pinout at 1c3d.com/tools/pinouts — select Microcontroller → Flipper Zero GPIO.
Quick Pinout Reference
| Pin | Name | Function |
|---|---|---|
| 1 | 5V | Power out (OFF by default) |
| 2 | PA7 | GPIO, ADC, PWM |
| 3 | PA6 | GPIO, ADC |
| 4 | PA4 | GPIO, comparator |
| 5 | PB3 | GPIO, SWO |
| 6 | PB2 | GPIO |
| 7 | PC3 | GPIO, ADC |
| 8 | GND | Ground |
| 9 | 3.3V | Power out (ON by default) |
| 10 | SWCLK | SWD debug clock |
| 11 | GND | Ground |
| 12 | SWDIO (PA13) | SWD debug data |
| 13 | TX (PB6) | USART1 TX |
| 14 | RX (PB7) | USART1 RX |
| 15 | PC1 | GPIO, ADC, alt UART TX |
| 16 | PC0 | GPIO, ADC, alt UART RX |
| 17 | PB14 | 1-Wire / iButton |
| 18 | GND | Ground |
Critical Rules
All GPIO pins are 3.3V logic. Applying 5V to any GPIO pin will damage the STM32WB55. Use a level shifter (TXS0108E or simple voltage divider) for any 5V device.
Pin 1 (5V) is OFF by default. Enable: Main Menu → GPIO → 5V on GPIO pin. Max 1.2A per rail, 5W total GPIO budget across all pins.
UART Serial (Pins 13 and 14)
Default: 115200 baud, 8N1.
Flipper TX (pin 13) → Adapter RX
Flipper RX (pin 14) → Adapter TX
Flipper GND (pin 8) → Adapter GNDIn the Flipper UI: Main Menu → GPIO → USB-UART Bridge creates a virtual COM port over USB.
GPS Module Wiring
GPS TX → Flipper RX (pin 14)
GPS RX → Flipper TX (pin 13)
GPS VCC → Flipper 3.3V (pin 9)
GPS GND → Flipper GND (pin 8)Use the GPS app in Unleashed or Momentum firmware.
DS18B20 Temperature Sensor (1-Wire, Pin 17)
Pin 17 has a built-in 1kΩ pull-up to 5V — no external resistor needed:
DS18B20 DQ → Pin 17 (PB14)
DS18B20 VCC → Pin 9 (3.3V)
DS18B20 GND → Pin 8 (GND)ADC — Analog Inputs (Pins 2, 3, 4, 7)
Input range 0-3.3V, 12-bit resolution. Potentiometer example:
Pot wiper → Pin 2 (PA7)
Pot high end → Pin 9 (3.3V)
Pot low end → Pin 8 (GND)Popular GPIO Projects
| Project | Pins Used | Notes |
|---|---|---|
| Serial console | 13, 14, 8 | USB-UART bridge app |
| GPS receiver | 14, 13, 9, 8 | NMEA, GPS app |
| DS18B20 temp sensor | 17, 9, 8 | 1-Wire built-in |
| Logic analyzer | 2-7 | Logic Analyzer app |
| SWD debug probe | 10, 12, 8 | Black Magic Probe firmware |
| NeoPixel LEDs | Any GPIO | Custom app, 5V for LED power |
WiFi DevBoard (ESP32-S2)
The official WiFi DevBoard plugs directly into the 18-pin header and handles level shifting and power internally. It runs Marauder firmware for WiFi scanning and attacks.
Related
- Full interactive Flipper Zero pinout — Microcontroller → Flipper Zero GPIO
- Flipper Zero WiFi Multi-Tool guide
- UART TTL pinout reference
- ARM SWD pinout reference