RPIO 0.7.1

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

Installation

The easiest way to install/update RPIO on a Raspberry Pi is with either easy_install or pip (you may need to get it first with sudo apt-get install python-setuptools):

$ sudo easy_install -U RPIO
$ sudo pip install -U RPIO

Another way to get RPIO is directly from the Github repository:

$ 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 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>`.

Show interrupt events on GPIOs (with -w/--wait_for_interrupts;
default edge='both'):

    $ rpio -w 7
    $ rpio -w 7:rising,8:falling,9
    $ rpio -w 1-9

Setup a pin as INPUT (optionally with pullup or -down resistor):

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

Setup a pin as OUTPUT:

    $ rpio --setoutput 8

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 a few other goodies.

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, edge='rising')
RPIO.add_interrupt_callback(8, do_something, edge='falling')
RPIO.add_interrupt_callback(9, do_something, edge='both')
RPIO.wait_for_interrupts()

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, edge='rising', 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().

Please note that you don’t need to call setup(..) for a gpio before using it for interrupts, pullup/pulldown resistors are not available and only BCM gpio numbering is supported (although BOARD will be included shortly).

RPi.GPIO

Besides the interrupt handling, you can use RPIO just as RPi.GPIO:

import RPIO

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

# set up input channel with pull-up control
#   (pull_up_down be PUD_OFF, PUD_UP or PUD_DOWN, default PUD_OFF)
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(18, RPIO.OUT, initial=RPIO.LOW)

# change to BOARD numbering schema (interrupts will still use BCM though)
RPIO.setmode(RPIO.BOARD)

# reset every channel that has been set up by this program. and unexport 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`)

Additions to RPi.GPIO

Additional Constants

• RPIO.RPI_REVISION (either 1 or 2)

• RPIO.RPI_REVISION_HEX (0002 .. 000f)

Additional Methods

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

• RPIO.is_valid_gpio_id(gpio_id) - returns True if the supplied gpio_id is valid on this board

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

Interrupt Handling

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

• RPIO.del_interrupt_callback(gpio_id)

• RPIO.wait_for_interrupts(epoll_timeout=1)

• RPIO.stop_waiting_for_interrupts()

• implemented with epoll

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

Feedback

Please send any feedback to Chris Hager ([e-mail]) and open an issue at Github if you’ve encountered a bug.

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.

Updates

• 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