pigpio library
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The pigpio library

pigpio is a library for the Raspberry which allows control of the General Purpose Input Outputs (GPIO).  pigpio works on all versions of the Pi. Download.

Features

  • hardware timed sampling and time-stamping of GPIO 0-31 every 5 µs

  • hardware timed PWM on all of GPIO 0-31

  • hardware timed servo pulses on all of GPIO 0-31

  • callbacks on GPIO 0-31 level change (time accurate to a few µs)

  • notifications via pipe on GPIO 0-31 level change

  • callbacks at timed intervals

  • reading/writing all of the GPIO in a bank (0-31, 32-53) as a single operation

  • GPIO reading, writing, modes, and internal pulls

  • socket and pipe interfaces for the bulk of the functionality

  • waveforms to generate GPIO level changes (time accurate to a few µs)

  • software serial links using any user GPIO

  • rudimentary permission control through the socket and pipe interfaces

  • creating and running scripts on the pigpio daemon

General

The pigpio library is written in the C programming language.

The pigpio daemon offers a socket and pipe interface to the underlying C library.

A C library and a Python module allow control of the GPIO via the pigpio daemon.

There is third party support for a number of other languages

piscope

piscope is a digital waveform viewer.

piscope is a GTK+3 application and uses pigpio to provide raw GPIO level data.  piscope may be run on a Pi or on any machine capable of compiling a GTK+3 application.

GPIO

ALL GPIO are identified by their Broadcom number.  See elinux.org

There are 54 GPIO in total, arranged in two banks.

Bank 1 contains GPIO 0-31.  Bank 2 contains GPIO 32-53.

There are several types of board, each with different expansion headers, giving physical access to different GPIO. 

Type 1 - Model B (original model)

  • 26 pin header (P1).
  • Hardware revision numbers of 2 and 3.
  • User GPIO 0-1, 4, 7-11, 14-15, 17-18, 21-25.

GPIO pin pin GPIO
3V3 - 1 2 - 5V
SDA 0
3 4 - 5V
SCL 1
5 6 - Ground

4 7 8 14 TXD
Ground - 9 10 15 RXD
ce1 17 11 12 18 ce0

21 13 14 - Ground

22 15 16 23
3V3 -
17 18 24
MOSI 10 19 20 - Ground
MISO 9 21 22 25
SCLK 11 23 24 8 CE0
Ground - 25 26 7 CE1

Type 2 - Model A, B (revision 2)

26 pin header (P1) and an additional 8 pin header (P5).
  • Hardware revision numbers of 4, 5, 6 (B), 7, 8, 9 (A), and 13, 14, 15 (B).
  • User GPIO 2-4, 7-11, 14-15, 17-18, 22-25, 27-31.

GPIO pin pin GPIO
3V3 - 1 2 - 5V
SDA 2 3 4 - 5V
SCL 3 5 6 - Ground

4 7 8 14 TXD
Ground - 9 10 15 RXD
ce1 17 11 12 18 ce0

27 13 14 - Ground

22 15 16 23
3V3 -
17 18 24
MOSI 10 19 20 - Ground
MISO 9 21 22 25
SCLK 11 23 24 8 CE0
Ground - 25 26 7 CE1


GPIO pin pin GPIO
5V
- 1 2 - 3V3
SDA
28 3 4 29 SCL

30 5 6 31
Ground
-
7 8 -
Ground

Type 3 - Model A+, B+, Pi Zero, Pi2B, Pi3B

  • 40 pin expansion header (J8).
  • Hardware revision numbers of 16 or greater.
  • User GPIO 2-27 (0 and 1 are reserved).

GPIO pin pin GPIO
3V3 - 1 2 - 5V
SDA 2 3 4 - 5V
SCL 3 5 6 - Ground

4 7 8 14 TXD
Ground - 9 10 15 RXD
ce1 17 11 12 18 ce0

27 13 14 - Ground

22 15 16 23
3V3 -
17 18 24
MOSI 10 19 20 - Ground
MISO 9 21 22 25
SCLK 11 23 24 8 CE0
Ground - 25 26 7 CE1
ID_SD 0 27 28 1 ID_SC

5 29 30 - Ground

6 31 32 12

13 33 34 - Ground
miso 19 35 36 16 ce2

26 37 38 20 mosi
Ground - 39 40 21 sclk

Compute Module

All 54 GPIO may be physically accessed.  Some are reserved for system use - refer to the Compute Module documentation.

For all types of Pi it is safe to read the GPIO. If you try to write a system GPIO or change its mode you can crash the Pi or corrupt the data on the SD card.

Other Languages

There are several third party projects which provide wrappers for pigpio.

Some I am aware of are


The PWM and servo pulses are timed using the DMA and PWM/PCM peripherals.  This use was inspired by Richard Hirst's servoblaster kernel module.

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e-mail: pigpio @ abyz.co.uk
Updated: 12/06/2016