An open API service indexing awesome lists of open source software.

https://github.com/adafruit/adafruit-beaglebone-io-python

Adafruit's BeagleBone IO Python Library
https://github.com/adafruit/adafruit-beaglebone-io-python

beaglebone beaglebone-black python

Last synced: 7 months ago
JSON representation

Adafruit's BeagleBone IO Python Library

Awesome Lists containing this project

README

          

# Adafruit Beaglebone I/O Python API

[![Documentation Status](https://readthedocs.org/projects/adafruit-beaglebone-io-python/badge/?version=latest)](http://adafruit-beaglebone-io-python.readthedocs.io/en/latest/?badge=latest)
[![PyPI version](https://badge.fury.io/py/Adafruit_BBIO.svg)](https://badge.fury.io/py/Adafruit_BBIO)
[![PyPI pyversions](https://img.shields.io/pypi/pyversions/Adafruit_BBIO.svg)](https://pypi.python.org/pypi/Adafruit_BBIO/)

Adafruit BBIO is an API to enable [GPIO](README.md#gpio-setup), [PWM](README.md#pwm), [ADC](README.md#adc), [UART](README.md#uart), [SPI](README.md#spi) and [eQEP](README.md#eqep) (Quadrature Encoder) hardware access from Python applications running on the Beaglebone.

* It is recommended to use an [official BeagleBoard.org Debian image](https://beagleboard.org/latest-images)
* **Currently recommended image: [Debian 10.3 "Buster" IoT (2020-04-06)](http://beagleboard.org/latest-images)** _(default kernel is 4.19.x-ti)_

* Adafruit_BBIO supports Linux kernels 3.8 through 4.19

* New versions of Adafruit_BBIO may break backwards compatibility. Please read the [changelog](CHANGELOG.md).

* It is recommended to use Python 3

## Installation on Debian

Note: Follow the instructions on BeagleBoard.org to [get connected to the Internet](https://beagleboard.org/upgrade#connect)

**Easiest:**
```
sudo apt-get update
sudo apt-get install build-essential python3-dev python3-pip -y
sudo pip3 install Adafruit_BBIO
```

**Manual:**
```
sudo apt-get update
sudo apt-get install build-essential python3-dev python3-pip -y
git clone git://github.com/adafruit/adafruit-beaglebone-io-python.git
cd adafruit-beaglebone-io-python
sudo python3 setup.py install
```

Upgrade Adafruit_BBIO to latest version on [PyPI](https://pypi.python.org/pypi/Adafruit_BBIO):
```
sudo pip3 install --upgrade Adafruit_BBIO
```

## Usage

Using the library is very similar to the excellent RPi.GPIO library used on the Raspberry Pi. Below are some examples.

### Pin Numbers

Please note that there is no '0' prefix for the pin numbers. For example, pin 7 on header P8 is `P8_7`.

**Correct:**
```
GPIO.setup("P8_7", OUT )
```

**INCORRECT:**
```
GPIO.setup("P8_07", OUT )
```

Refer to `pins_t table[]` in [common.c](https://github.com/adafruit/adafruit-beaglebone-io-python/blob/master/source/common.c#L73) all the pin labels.

### config-pin

[config-pin](https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io) is now used on the official BeagleBoard.org Debian Jessie and Stretch images to control pin mode (e.g. pin mux).

```
debian@beaglebone:~$ config-pin -q P9_14
P9_14 Mode: pwm

debian@beaglebone:~$ config-pin -l P9_14
default gpio gpio_pu gpio_pd pwm

debian@beaglebone:~$ config-pin P9_14 gpio

debian@beaglebone:~$ config-pin -q P9_14
P9_14 Mode: gpio Direction: in Value: 0

debian@beaglebone:~$ config-pin P9_14 pwm

debian@beaglebone:~$ config-pin -q P9_14
P9_14 Mode: pwm
```

### GPIO Setup

Import the library, and setup as GPIO.OUT or GPIO.IN::

import Adafruit_BBIO.GPIO as GPIO
GPIO.setup("P8_14", GPIO.OUT)

You can also refer to the pin names::

GPIO.setup("GPIO0_26", GPIO.OUT)

### GPIO Output

Setup the pin for output, and write GPIO.HIGH or GPIO.LOW. Or you can use 1 or 0.::

import Adafruit_BBIO.GPIO as GPIO
GPIO.setup("P8_14", GPIO.OUT)
GPIO.output("P8_14", GPIO.HIGH)

### On-Board LEDs

On-board LEDs (USR0-USR3) are handled by LED class driver rather than the GPIO pin driver.

They have a different path in the /sys/ filesystem.

Setup the pin for output and write GPIO.HIGH or GPIO.LOW::

import Adafruit_BBIO.GPIO as GPIO
import time

for i in range(4):
GPIO.setup("USR%d" % i, GPIO.OUT)

while True:
for i in range(4):
GPIO.output("USR%d" % i, GPIO.HIGH)
time.sleep(1)
for i in range(4):
GPIO.output("USR%d" % i, GPIO.LOW)
time.sleep(1)

### GPIO Input

Inputs work similarly to outputs.:

import Adafruit_BBIO.GPIO as GPIO
GPIO.setup("P8_14", GPIO.IN)

Polling inputs:

if GPIO.input("P8_14"):
print("HIGH")
else:
print("LOW")

Waiting for an edge (GPIO.RISING, GPIO.FALLING, or GPIO.BOTH:

GPIO.wait_for_edge(channel, GPIO.RISING)

or

GPIO.wait_for_edge(channel, GPIO.RISING, timeout)

Detecting events:

GPIO.add_event_detect("P9_12", GPIO.FALLING)
#your amazing code here
#detect wherever:
if GPIO.event_detected("P9_12"):
print("event detected!")

### PWM
**The PWM Duty Cycle range was reversed in 0.0.15 from 100(off)-0(on) to 0(off)-100(on). Please update your code accordingly.**

import Adafruit_BBIO.PWM as PWM
#PWM.start(channel, duty, freq=2000, polarity=0)
#duty values are valid 0 (off) to 100 (on)
PWM.start("P9_14", 50)
PWM.set_duty_cycle("P9_14", 25.5)
PWM.set_frequency("P9_14", 10)

PWM.stop("P9_14")
PWM.cleanup()

#set polarity to 1 on start:
PWM.start("P9_14", 50, 2000, 1)

### ADC

import Adafruit_BBIO.ADC as ADC
ADC.setup()

#read returns values 0-1.0
value = ADC.read("P9_40")

#read_raw returns non-normalized value
value = ADC.read_raw("P9_40")

### [UART](https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/uart)
* Use [`config-pin` to set pin mode](https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io) for [UART1 and UART2 pins](http://beagleboard.org/static/images/cape-headers-serial.png)
```
config-pin P9.21 uart # UART2_TXD
config-pin P9.22 uart # UART2_RXD
config-pin P9.24 uart # UART1_TXD
config-pin P9.26 uart # UART1_RXD
```
* [Install pyserial](https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/uart#using-uart-with-python)
```
sudo pip install pyserial
```
* [Test UART1](https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/uart#using-uart-with-python)
```
import Adafruit_BBIO.UART as UART
import serial

UART.setup("UART1")

with serial.Serial(port = "/dev/ttyO1", baudrate=9600) as ser:
print("Serial is open!")
ser.write(b"Hello World!")

```
* Available UART names on BeagleBone
* `UART1`: /dev/ttyO1, Rx: P9_26, Tx: P9_24
* `UART2`: /dev/ttyO2, Rx: P9_22, Tx: P9_21
* `UART4`: /dev/ttyO4, Rx: P9_11, Tx: P9_13
* `UART5`: /dev/ttyO5, Rx: P8_38, Tx: P8_37
* note: `UART5` requires `disable_uboot_overlay_video=1` in `/boot/uEnv.txt`
* Available UART names on PocketBeagle
* `PB-UART0`: /dev/ttyO0, Rx: P1_30, Tx: P1_32
* `PB-UART1`: /dev/ttyO1, Rx: P2_11, Tx: P2_09
* `PB-UART2`: /dev/ttyO2, Rx: P1_08, Tx: P1_10
* [Loopback test with UART1 and UART2](https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/uart#testing-and-using-the-uart)

### [SPI](https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/spi)
* Use [`config-pin` to set pin mode](https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io) for [SPI pins](http://beagleboard.org/static/images/cape-headers-spi.png)
* SPI0
* SPI0_CS0: `config-pin p9.17 spi_cs`
* SPI0_D0: `config-pin p9.21 spi`
* SPI0_D1: `config-pin p9.18 spi`
* SPI0_SCLK: `config-pin p9.22 spi_sclk`
* SPI1
* SPI1_CS0: `config-pin p9.20 spi_cs`
* SPI1_CS0: `config-pin p9.28 spi_cs`
* SPI1_CS1: `config-pin p9.19 spi_cs`
* SPI1_CS1: `config-pin p9.42 spi_cs`
* SPI1_D0: `config-pin p9.29 spi`
* SPI1_D1: `config-pin p9.30 spi`
* SPI1_SCLK: `config-pin p9.31 spi_sclk`
* Example:
```
from Adafruit_BBIO.SPI import SPI
#spi = SPI(bus, device) #/dev/spidev.

# /dev/spidev0.0
spi = SPI(1,0)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close()

# /dev/spidev0.1
spi = SPI(1,1)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close()

# /dev/spidev1.0
spi = SPI(2,0)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close()

# /dev/spidev1.1
spi = SPI(2,1)
print(spi.xfer2([32, 11, 110, 22, 220]))
spi.close()
```

### eQEP

To use the enhanced Quadrature Encoder Pulse (eQEP) module, please refer to the [`Encoder` module's documentation](https://github.com/adafruit/adafruit-beaglebone-io-python/tree/master/Adafruit_BBIO#usage).

## Running tests

Install py.test to run the tests. You'll also need the python compiler package for pytest:
```
sudo pip3 install pytest
```
Execute the following in the root of the project:
```
pytest
```
NOTE: `sudo` should not be required as udev configures group ownership and permission for [GPIO](https://github.com/rcn-ee/repos/blob/master/bb-customizations/suite/stretch/debian/80-gpio-noroot.rules) and [PWM](https://github.com/rcn-ee/repos/blob/master/bb-customizations/suite/stretch/debian/81-pwm-noroot.rules)

## Reporting issues

When reporting issues, plesae run the following script which will print the system configuration:
```
sudo /opt/scripts/tools/version.sh
```
and paste the output in a reply.

This script should be present for any Debian or Ubunut image downloaded from:
https://beagleboard.org/ or https://rcn-ee.com/

## Credits

The BeagleBone IO Python library was originally forked from the excellent MIT Licensed [RPi.GPIO](https://code.google.com/p/raspberry-gpio-python) library written by Ben Croston.

## License

Written by Justin Cooper, Adafruit Industries. BeagleBone IO Python library is released under the MIT License.