Beaglebone_Black.py

# Copyright (c) 2014 Adafruit Industries
# Author: Tony DiCola

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import re

from . import common
from . import Beaglebone_Black_Driver as driver


# Define mapping of pin names to GPIO base and number.
# Adapted from Adafruit_BBIO code Beaglebone Black system reference.
pin_to_gpio = {
    "P9_11": (0,30),
    "P9_12": (1,28),
    "P9_13": (0,31),
    "P9_14": (1,18),
    "P9_15": (1,16),
    "P9_16": (1,19),
    "P9_17": (0,5),
    "P9_18": (0,4),
    "P9_19": (0,13),
    "P9_20": (0,12),
    "P9_21": (0,3),
    "P9_22": (0,2),
    "P9_23": (1,17),
    "P9_24": (0,15),
    "P9_25": (3,21),
    "P9_26": (0,14),
    "P9_27": (3,19),
    "P9_28": (3,17),
    "P9_29": (3,15),
    "P9_30": (3,16),
    "P9_31": (3,14),
    "P9_41": (0,20),
    "P9_42": (0,7),
    "UART4_RXD": (0,30),
    "UART4_TXD": (0,31),
    "EHRPWM1A": (1,18),
    "EHRPWM1B": (1,19),
    "I2C1_SCL": (0,5),
    "I2C1_SDA": (0,4),
    "I2C2_SCL": (0,13),
    "I2C2_SDA": (0,12),
    "UART2_TXD": (0,3),
    "UART2_RXD": (0,2),
    "UART1_TXD": (0,15),
    "UART1_RXD": (0,14),
    "SPI1_CS0": (3,17),
    "SPI1_D0": (3,15),
    "SPI1_D1": (3,16),
    "SPI1_SCLK": (3,14),
    "CLKOUT2": (0,20),
    "30": (0,30),
    "60": (1,28),
    "31": (0,31),
    "50": (1,18),
    "48": (1,16),
    "51": (1,19),
    "5": (0,5),
    "4": (0,4),
    "13": (0,13),
    "12": (0,12),
    "3": (0,3),
    "2": (0,2),
    "49": (1,17),
    "15": (0,15),
    "117": (3,21),
    "14": (0,14),
    "115": (3,19),
    "113": (3,17),
    "111": (3,15),
    "112": (3,16),
    "110": (3,14),
    "20": (0,20),
    "7": (0,7),
    "P8_3": (1,6),
    "P8_4": (1,7),
    "P8_5": (1,2),
    "P8_6": (1,3),
    "P8_7": (2,2),
    "P8_8": (2,3),
    "P8_9": (2,5),
    "P8_10": (2,4),
    "P8_11": (1,13),
    "P8_12": (1,12),
    "P8_13": (0,23),
    "P8_14": (0,26),
    "P8_15": (1,15),
    "P8_16": (1,14),
    "P8_17": (0,27),
    "P8_18": (2,1),
    "P8_19": (0,22),
    "P8_20": (1,31),
    "P8_21": (1,30),
    "P8_22": (1,5),
    "P8_23": (1,4),
    "P8_24": (1,1),
    "P8_25": (1,0),
    "P8_26": (1,29),
    "P8_27": (2,22),
    "P8_28": (2,24),
    "P8_29": (2,23),
    "P8_30": (2,25),
    "P8_31": (0,10),
    "P8_32": (0,11),
    "P8_33": (0,9),
    "P8_34": (2,17),
    "P8_35": (0,8),
    "P8_36": (2,16),
    "P8_37": (2,14),
    "P8_38": (2,15),
    "P8_39": (2,12),
    "P8_40": (2,13),
    "P8_41": (2,10),
    "P8_42": (2,11),
    "P8_43": (2,8),
    "P8_44": (2,9),
    "P8_45": (2,6),
    "P8_46": (2,7),
    "TIMER4": (2,2),
    "TIMER7": (2,3),
    "TIMER5": (2,5),
    "TIMER6": (2,4),
    "EHRPWM2B": (0,23),
    "EHRPWM2A": (0,22),
    "UART5_CTSN": (0,10),
    "UART5_RTSN": (0,11),
    "UART4_RTSN": (0,9),
    "UART3_RTSN": (2,17),
    "UART4_CTSN": (0,8),
    "UART3_CTSN": (2,16),
    "UART5_TXD": (2,14),
    "UART5_RXD": (2,15),
    "38": (1,6),
    "39": (1,7),
    "34": (1,2),
    "35": (1,3),
    "66": (2,2),
    "67": (2,3),
    "69": (2,5),
    "68": (2,4),
    "45": (1,13),
    "44": (1,12),
    "23": (0,23),
    "26": (0,26),
    "47": (1,15),
    "46": (1,14),
    "27": (0,27),
    "65": (2,1),
    "22": (0,22),
    "63": (1,31),
    "62": (1,30),
    "37": (1,5),
    "36": (1,4),
    "33": (1,1),
    "32": (1,0),
    "61": (1,29),
    "86": (2,22),
    "88": (2,24),
    "87": (2,23),
    "89": (2,25),
    "10": (0,10),
    "11": (0,11),
    "9": (0,9),
    "81": (2,17),
    "8": (0,8),
    "80": (2,16),
    "78": (2,14),
    "79": (2,15),
    "76": (2,12),
    "77": (2,13),
    "74": (2,10),
    "75": (2,11),
    "72": (2,8),
    "73": (2,9),
    "70": (2,6),
    "71": (2,7)
}

def read(sensor, pin):
    # Validate GPIO and map it to GPIO base and number.
    gpio = pin_to_gpio.get(str(pin).upper(), None)
    if gpio is None:
        # Couldn't find in mapping, check if pin looks like GPIO<base>_<number>
        match = re.match('GPIO([0123])_(\d+)', pin, re.IGNORECASE)
        if match is not None:
            gpio = (int(match.group(1)), int(match.group(2)))
    if gpio is None or gpio[0] < 0 or gpio[0] > 3 or gpio[1] < 0 or gpio[1] > 31:
        raise ValueError('Pin must be a valid GPIO identifier like P9_12 or GPIO1_28.')
    # Get a reading from C driver code.
    result, humidity, temp = driver.read(sensor, gpio[0], gpio[1])
    if result in common.TRANSIENT_ERRORS:
        # Signal no result could be obtained, but the caller can retry.
        return (None, None)
    elif result == common.DHT_ERROR_GPIO:
        raise RuntimeError('Error accessing GPIO. Make sure program is run as root with sudo!')
    elif result != common.DHT_SUCCESS:
        # Some kind of error occured.
        raise RuntimeError('Error calling DHT test driver read: {0}'.format(result))
    return (humidity, temp)