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

import Adafruit_DHT.common as common
import Adafruit_DHT.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)