1-WIRE At Raspberry Pi GPIO Pinout

• 3v3 Power1
• GPIO 2 (I2C1 SDA)3
• GPIO 3 (I2C1 SCL)5
• GPIO 4 (Data)7
• Ground9
• GPIO 1711
• GPIO 2713
• GPIO 2215
• 3v3 Power17
• GPIO 10 (SPI0 MOSI)19
• GPIO 9 (SPI0 MISO)21
• GPIO 11 (SPI0 SCLK)23
• Ground25
• GPIO 0 (EEPROM SDA)27
• GPIO 529
• GPIO 631
• GPIO 13 (PWM1)33
• GPIO 19 (PCM FS)35
• GPIO 2637
• Ground39

• 5v Power2
• 5v Power4
• Ground6
• GPIO 14 (UART0 TX)8
• GPIO 15 (UART0 RX)10
• GPIO 18 (PCM CLK)12
• Ground14
• GPIO 2316
• GPIO 2418
• Ground20
• GPIO 2522
• GPIO 8 (SPI0 CE0)24
• GPIO 7 (SPI0 CE1)26
• GPIO 1 (EEPROM SCL)28
• Ground30
• GPIO 12 (PWM0)32
• Ground34
• GPIO 1636
• GPIO 20 (PCM DIN)38
• GPIO 21 (PCM DOUT)40

Legend

Orientate your Pi with the GPIO on the right and the HDMI port(s) on the left.

• GPIO (General Purpose IO)
• SPI (Serial Peripheral Interface)
• I2C (Inter-integrated Circuit)
• UART (Universal Asynchronous Receiver/Transmitter)
• PCM (Pulse Code Modulation)
• Ground
• 5v (Power)
• 3.3v (Power)

Support Pinout, build with PCBWay

• 3v3 Power
• 5v Power
• Ground
• 1-WIRE
• DPI
• GPCLK
• I2C
• JTAG
• PCM
• PWM
• SDIO
• SPI
• UART
• WiringPi

Click here to browse pinouts for HATs & pHATs »

W1-GPIO - One-Wire Interface

One-wire is a single-wire communication bus typically used to connect sensors to the Pi.

The Raspberry Pi supports one-wire on any GPIO pin, but the default is GPIO 4.

Enable via config.txt

To enable the one-wire interface you need to add the following line to /boot/firmware/config.txt, before rebooting your Pi:

dtoverlay=w1-gpio

or

dtoverlay=w1-gpio,gpiopin=x

if you would like to use a custom pin (the default is GPIO 4)

Enable manually

Alternatively you can enable the one-wire interface on demand using raspi-config, or the following:

sudo modprobe w1-gpio

Newer kernels (4.9.28 and later) allow you to use dynamic overlay loading instead, including creating multiple 1-Wire buses to be used at the same time:

sudo dtoverlay w1-gpio gpiopin=4 pullup=0 # header pin 7 sudo dtoverlay w1-gpio gpiopin=17 pullup=0 # header pin 11 sudo dtoverlay w1-gpio gpiopin=27 pullup=0 # header pin 13

once any of the steps above have been performed, and discovery is complete you can list the devices that your Raspberry Pi has discovered via all 1-Wire buses (by default GPIO 4), like so:

ls /sys/bus/w1/devices/

Using w1-gpio on the Raspberry Pi typically needs a 4.7 kΩ pull-up resistor connected between the GPIO pin and a 3.3v supply (e.g. header pin 1 or 17). Other means of connecting 1-Wire devices to the Raspberry Pi are also possible, such as using i2c to 1-Wire bridge chips.

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