RPIO 0.8.0

GPIO toolbox for the Raspberry Pi. Extends RPi.GPIO with interrups, a command line tool and more

Visit pythonhosted.org/RPIO for a pretty version of this documentation.

RPIO is a GPIO toolbox for the Raspberry Pi.

• RPIO.py, an extension of RPi.GPIO with interrupt handling and more

• rpio, a command-line multitool for inspecting and manipulating GPIOs system-wide

Installation

The easiest way to install/update RPIO on a Raspberry Pi is with either easy_install or pip:

$ sudo apt-get install python-pip
$ sudo pip install -U RPIO

Another way to get RPIO is directly from the Github repository (make sure you have python-dev installed):

$ git clone https://github.com/metachris/RPIO.git
$ cd RPIO
$ sudo python setup.py install

After the installation you can use import RPIO as well as the command-line tool rpio.

rpio, the command line tool

rpio allows you to inspect and manipulate GPIO’s system wide, including those used by other processes. rpio needs to run with superuser privileges (root), else it will restart using sudo. The BCM GPIO numbering scheme is used by default.

Show the help page:

    $ rpio -h

Inspect the function and state of gpios (with -i/--inspect):

    $ rpio -i 7
    $ rpio -i 7,8,9
    $ rpio -i 1-9

    # Example output for `rpio -i 1-9` (non-existing are ommitted):
    GPIO 2: ALT0   (1)
    GPIO 3: ALT0   (1)
    GPIO 4: INPUT  (0)
    GPIO 7: OUTPUT (0)
    GPIO 8: INPUT  (1)
    GPIO 9: INPUT  (0)

Inspect all GPIO's on this board (with -I/--inspect-all):

    $ rpio -I

Set GPIO 7 output to `1` (or `0`) (with -s/--set):

    $ rpio -s 7:1

    You can only write to pins that have been set up as OUTPUT. You can
    set this yourself with `--setoutput <gpio-id>`.

Wait for interrupt events on GPIOs (with -w/--wait_for_interrupts). You
can specify an edge (eg. `:rising`; default='both') as well as `:pullup`,
`:pulldown` or `pulloff`.

    $ rpio -w 7
    $ rpio -w 7:rising
    $ rpio -w 7:falling:pullup

    $ rpio -w 7:rising:pullup,17,18
    $ rpio -w 1-9

Setup a pin as INPUT (optionally with software resistor):

    $ rpio --setinput 7
    $ rpio --setinput 7:pullup
    $ rpio --setinput 7:pulldown

Setup a pin as OUTPUT (optionally with an initial value (0 or 1)):

    $ rpio --setoutput 8
    $ rpio --setoutput 8:1

Show Raspberry Pi system info:

    $ rpio --sysinfo

    # Example output:
    Model B, Revision 2.0, RAM: 256 MB, Maker: Sony

You can update the RPIO package to the latest version:

$ rpio --update-rpio

Install (and update) the rpio manpage:

$ rpio --update-man
$ man rpio

RPIO.py, the Python module

RPIO.py extends RPi.GPIO with interrupt handling and more.

Interrupts are used to receive notifications from the kernel when GPIO state changes occur. Advantages include minimized cpu consumption, very fast notification times, and the ability to trigger on specific edge transitions (rising|falling|both). RPIO uses the BCM GPIO numbering scheme by default. This is an example of how to use RPIO to react on events on 3 pins by using interrupts, each with different edge detections:

# Setup logging
import logging
log_format = '%(levelname)s | %(asctime)-15s | %(message)s'
logging.basicConfig(format=log_format, level=logging.DEBUG)

# Get started
import RPIO

def do_something(gpio_id, value):
    logging.info("New value for GPIO %s: %s" % (gpio_id, value))

RPIO.add_interrupt_callback(7, do_something)
RPIO.add_interrupt_callback(8, do_something, edge='rising')
RPIO.add_interrupt_callback(9, do_something, pull_up_down=RPIO.PUD_UP)
RPIO.wait_for_interrupts()

Default edge is both and default pull_up_down is RPIO.PUD_OFF. If you want to receive a callback inside a Thread (which won’t block anything else on the system), set threaded_callback=True when adding an interrupt- callback. Here is an example:

RPIO.add_interrupt_callback(7, do_something, threaded_callback=True)

Make sure to double-check the value returned from the interrupt, since it is not necessarily corresponding to the edge (eg. 0 may come in as value, even if edge=”rising”). To remove all callbacks from a certain gpio pin, use RPIO.del_interrupt_callback(gpio_id). To stop the wait_for_interrupts() loop you can call RPIO.stop_waiting_for_interrupts().

GPIO Input & Output

RPIO extends RPi.GPIO; all the input and output handling works just the same:

import RPIO

# set up input channel without pull-up
RPIO.setup(7, RPIO.IN)

# set up input channel with pull-up control. Can be
# PUD_UP, PUD_DOWN or PUD_OFF (default)
RPIO.setup(7, RPIO.IN, pull_up_down=RPIO.PUD_UP)

# read input from gpio 7
input_value = RPIO.input(7)

# set up GPIO output channel
RPIO.setup(8, RPIO.OUT)

# set gpio 8 to high
RPIO.output(8, True)

# set up output channel with an initial state
RPIO.setup(8, RPIO.OUT, initial=RPIO.LOW)

# change to BOARD numbering schema
RPIO.setmode(RPIO.BOARD)

# set software pullup on channel 17
RPIO.set_pullupdn(17, RPIO.PUD_UP)

# reset every channel that has been set up by this program,
# and unexport interrupt gpio interfaces
RPIO.cleanup()

You can use RPIO as a drop-in replacement for RPi.GPIO in your existing code like this:

import RPIO as GPIO  # (if you've previously used `import RPi.GPIO as GPIO`)

To find out more about the methods and constants in RPIO you can run $ sudo pydoc RPIO, or use the help method inside Python:

import RPIO
help(RPIO)

Additions to RPi.GPIO

Additional Constants

• RPIO.RPI_REVISION (either 1 or 2)

• RPIO.RPI_REVISION_HEX (0002 .. 000f)

Additional Methods

• RPIO.gpio_function(gpio_id) - returns the current setup of a gpio (IN, OUT, ALT0)

• RPIO.set_pullupdn(gpio_id, pud) - set a pullup or -down resistor on a GPIO

• RPIO.forceinput(gpio_id) - reads the value of any gpio without needing to call setup() first

• RPIO.forceoutput(gpio_id, value) - writes a value to any gpio without needing to call setup() first (warning: this can potentially harm your Raspberry)

• RPIO.rpi_sysinfo() - returns (model, revision, mb-ram and maker) of this Raspberry

Interrupt Handling

• RPIO.add_interrupt_callback(gpio_id, callback, edge='both', pull_up_down=RPIO.PUD_OFF, threaded_callback=False)

• RPIO.del_interrupt_callback(gpio_id)

• RPIO.wait_for_interrupts(epoll_timeout=1)

• RPIO.stop_waiting_for_interrupts()

• implemented with epoll

Feedback

Please send feedback and ideas to [e-mail], and open an issue at Github if you’ve encountered a bug.

FAQ

How does RPIO work?

RPIO extends RPi.GPIO, a GPIO controller written in C which uses a low-level memory interface. Interrupts are implemented with epoll via /sys/class/gpio/. For more detailled information take a look at the source, it’s well documented and easy to build.

Should I update RPIO often?

Yes, because RPIO is getting better by the day. You can use $ rpio --update-rpio or see Installation for more information about methods to update.

I’ve encountered a bug, what next?

• Make sure you are using the latest version of RPIO (see Installation)

• Open an issue at Github

  • Go to https://github.com/metachris/RPIO/issues/new

  • Describe the problem and steps to replicate

  • Add the output of $ rpio --version and $ rpio --sysinfo

pip is throwing an error during the build: source/c_gpio/py_gpio.c:9:20: fatal error: Python.h: No such file or directory

You need to install the python-dev package (eg. $ sudo apt-get install python-dev), or use easy_install (see Installation).

Links

• https://github.com/metachris/RPIO

• http://pypi.python.org/pypi/RPIO

• http://pypi.python.org/pypi/RPi.GPIO

• http://www.kernel.org/doc/Documentation/gpio.txt

License

RPIO is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

RPIO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

Changes

• v0.8.0

  • Improved auto-cleaning of interrupt interfaces

  • BOARD numbering scheme support for interrupts

  • Support for software pullup and -down resistor with interrupts

  • New method RPIO.set_pullupdn(..)

  • rpio now supports P5 header gpios (28, 29, 30, 31) (only in BCM mode)

  • Tests added in source/run_tests.py and fabfile.py

  • Major refactoring of C GPIO code

  • Various minor updates and fixes

• v0.7.1

  • Refactoring and cleanup of c_gpio

  • Added new constants and methods (see documentation above)

  • Bugfixes

    • wait_for_interrupts() now auto-cleans interfaces when an exception occurs. Before you needed to call RPIO.cleanup() manually.

• v0.6.4

  • Python 3 bugfix in rpio

  • Various minor updates