From 2349fc1add0c1f5d2b38dafb8d52d3fc473b6abb Mon Sep 17 00:00:00 2001
From: Frederik Lindenaar <jfl@schutler.net>
Date: Sun, 3 Mar 2019 20:14:51 +0100
Subject: [PATCH] Added support for I2C MCP9808 sensor (closes #4) based on https://github.com/ControlEverythingCommunity/MCP9808/blob/master/Python/MCP9808.py
---
plugins/check_temperature | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 86 insertions(+), 20 deletions(-)
diff --git a/plugins/check_temperature b/plugins/check_temperature
index 34a106f..450758a 100755
--- a/plugins/check_temperature
+++ b/plugins/check_temperature
@@ -2,10 +2,10 @@
#
# check_temperature - Nagios temperature check for DS18B20 sensor on RaspberryPi
#
-# Version 1.1, latest version, documentation and bugtracker available at:
+# Version 1.2, latest version, documentation and bugtracker available at:
# https://gitlab.lindenaar.net/scripts/nagios-plugins
#
-# Copyright (c) 2017 Frederik Lindenaar
+# Copyright (c) 2017 - 2019 Frederik Lindenaar
#
# This script is free software: you can redistribute and/or modify it under the
# terms of version 3 of the GNU General Public License as published by the Free
@@ -27,15 +27,21 @@ from argparse import ArgumentParser as StandardArgumentParser, FileType, \
import logging
# Constants (no need to change but allows for easy customization)
-VERSION="1.1"
+VERSION="1.2"
PROG_NAME=splitext(basename(__file__))[0]
PROG_VERSION=PROG_NAME + ' ' + VERSION
-SENSOR_SCALE=1000
+
+CPU_SENSOR_DEV = '/sys/class/thermal/thermal_zone0/temp'
+I2C_MCP9808_CONFIG_ADDR=0x1
+I2C_MCP9808_CONFIG = [ 0x00, 0x00 ] # continuous conversion (power-up default)
+I2C_MCP9808_PRECISION_ADDR=0x08
+I2C_MCP9808_PRECISION=3 # 0=0.5, 1=0.25, 2=0.125, 3=0.0625 degr. C
+I2C_MCP9808_TEMP_ADDR=0x05
W1_SENSOR_DEV_DIR = '/sys/bus/w1/devices/'
W1_SENSOR_DEV_PREFIX = '28-'
W1_SENSOR_DEV_SUFFIX = '/w1_slave'
W1_SENSOR_READ_RETRIES=10
-CPU_SENSOR_DEV = '/sys/class/thermal/thermal_zone0/temp'
+W1_SENSOR_SCALE=1000
LOG_FORMAT='%(levelname)s - %(message)s'
LOG_FORMAT_FILE='%(asctime)s - ' + LOG_FORMAT
@@ -81,15 +87,15 @@ class SetLogFile(StoreAction):
###############################################################################
-def convert_celcius(temp_read):
+def convert_celcius(temp_read, scale = 1):
"""Converts raw temperature sensore value to degrees Celcius"""
- return float(temp_read) / float(SENSOR_SCALE)
+ return float(temp_read) / float(scale)
CONVERT_CELCIUS = ( convert_celcius, 'C', 'Celcius' )
-def convert_farenheit(temp_read):
+def convert_farenheit(temp_read, scale = 1):
"""Converts raw temperature sensore value to degrees Farenheit"""
- return float(temp_read * 9) / float(5 * SENSOR_SCALE) + 32.0
+ return float(temp_read * 9) / float(5 * scale) + 32.0
CONVERT_FARENHEIT = ( convert_farenheit, 'F', 'Farenheit' )
@@ -98,6 +104,11 @@ def isempty(string):
return string is None or len(string) == 0
+def hex_int(string):
+ """Use int()'s auto-detection to parse 10-base and 16-base (0x..) numbers"""
+ return int(string, 0);
+
+
def read_rpi_cpu_temp(args):
"""Reads CPU temperature and converts it to desired unit, returns temperature"""
with open(args.file, 'r') as f:
@@ -111,6 +122,51 @@ def read_rpi_cpu_temp(args):
return temp, 1
+def read_i2c_mcp9808_temp(args):
+ """Returns temperature from I2C MCP9808 sensor in desired unit"""
+
+ try:
+ import smbus
+ except ImportError:
+ try:
+ import smbus2 as smbus
+ except ImportError:
+ logger.critical("Unable to import either smbus or smbus2 library");
+ raise ImportError("missing I2C library, please install python-smbus or smbus2");
+
+ try:
+ bus = smbus.SMBus(args.i2cbus) # Get I2C bus
+ except OSError as e:
+ logger.critical(e)
+ raise IOError("Invalid I2C bus: %d" % args.i2cbus)
+
+ try:
+ bus.write_i2c_block_data(args.address, I2C_MCP9808_CONFIG_ADDR,
+ I2C_MCP9808_CONFIG)
+ bus.write_byte_data(args.address, I2C_MCP9808_PRECISION_ADDR,
+ I2C_MCP9808_PRECISION)
+ sleep(0.5)
+
+ # Read temperature (0x05), 2 bytes (MSB, LSB)
+ data = bus.read_i2c_block_data(args.address, I2C_MCP9808_TEMP_ADDR, 2)
+ logger.debug('Temperature sensor data from MCP9808 %#02x: 0x%02x%02x',
+ args.address, data[0], data[1])
+
+ # Convert the data to 13-bits
+ temp_read = ((data[0] & 0x1F) * 256) + data[1]
+ if temp_read > 4095 :
+ temp_read -= 8192
+
+ temp = args.converter[0](temp_read, 16)
+ logger.debug('Temperature sensor value %d is %.2f%s',
+ temp_read, temp, args.converter[1])
+ return temp, 1
+ except IOError as e:
+ logger.critical(e)
+ raise IOError("Error while communicating with I2C device %#02x" %
+ args.address)
+
+
def get_w1_sensor_device_filename(args, dev_dir=W1_SENSOR_DEV_DIR,
prefix=W1_SENSOR_DEV_PREFIX, suffix=W1_SENSOR_DEV_SUFFIX):
"""Auto-determine sensor datafile name (unless args.file is set)"""
@@ -138,8 +194,8 @@ def get_w1_sensor_device_filename(args, dev_dir=W1_SENSOR_DEV_DIR,
return filename
-def read_w1_temp(args):
- """Reads sensor data and converts it to desired unit, returns temperature"""
+def read_w1_ds18b20_temp(args):
+ """Returns temperature from 1-wire ds18b20 sensor in desired unit"""
device_file = get_w1_sensor_device_filename(args)
lines=[ '' ]
tries = 0
@@ -160,7 +216,7 @@ def read_w1_temp(args):
errmsg = 'temperature sensor data format is not supported'
else:
temp_read = int(lines[1][equals_pos+2:])
- temp = args.converter[0](temp_read)
+ temp = args.converter[0](temp_read, W1_SENSOR_SCALE)
logger.debug('Temperature sensor value %d is %.2f%s', temp_read,
temp, args.converter[1])
return temp, tries
@@ -174,11 +230,7 @@ def parse_args():
# Setup argument parser, the workhorse gluing it all together
parser = ArgumentParser(
- epilog='(*) by default the script will look for the first device that '
- 'matches %s* in %s, if multiple entries are found -s or -f must '
- 'be used to specify which sensor to read.' %
- (W1_SENSOR_DEV_PREFIX, W1_SENSOR_DEV_DIR),
- description='Nagios check plugin for 1-wire temp. sensor on RaspberryPi'
+ description='Nagios check plugin for temperature sensors on RaspberryPi'
)
parser.add_argument('-V', '--version',action="version",version=PROG_VERSION)
@@ -218,6 +270,16 @@ def parse_args():
help='read built-in Raspberry Pi CPU temperature')
cmdparser.set_defaults(func=read_rpi_cpu_temp, cmdparser=cmdparser, retries=0)
+ i2cparser = ArgumentParser(add_help=False)
+ i2cparser.add_argument('-a', '--address', type=hex_int,
+ help='I2C Address of sensor, use 0x.. for hex (*)')
+ i2cparser.add_argument('-b', '--i2cbus', default=1, type=int,
+ help='I2C Bus to use (defaults to 1)')
+ cmdparser = subparser.add_parser('i2c_mcp9808', parents=[i2cparser],
+ help='read I2C connected MCP9808 sensor',
+ epilog='(*) default I2C address for an MCP9808 is 0x18')
+ cmdparser.set_defaults(func=read_i2c_mcp9808_temp, cmdparser=cmdparser, retries=0, address=0x18)
+
w1parser = ArgumentParser(add_help=False)
pgroup = w1parser.add_mutually_exclusive_group(required=False)
pgroup.add_argument('-s', '--serial',
@@ -228,8 +290,12 @@ def parse_args():
help='number of times to retry reading sensor data when'
' unstable (defaults to %d)' % W1_SENSOR_READ_RETRIES)
cmdparser = subparser.add_parser('w1_ds18b20', parents=[w1parser],
- help='read 1-wire connected DS18b20 sensor')
- cmdparser.set_defaults(func=read_w1_temp, cmdparser=cmdparser)
+ help='read 1-wire connected DS18b20 sensor',
+ epilog='(*) by default the script will look for the first device that '
+ 'matches %s* in %s, if multiple entries are found -s or -f must '
+ 'be used to specify which sensor to read.' %
+ (W1_SENSOR_DEV_PREFIX, W1_SENSOR_DEV_DIR))
+ cmdparser.set_defaults(func=read_w1_ds18b20_temp, cmdparser=cmdparser)
# parse arguments and post-process command line options
args = parser.parse_args()
@@ -268,7 +334,7 @@ if __name__ == '__main__':
except (KeyboardInterrupt) as e:
nagios_exit(NAGIOS_UNKNOWN,'temperature sensor read aborted by user')
- except (IOError, ValueError) as e:
+ except (IOError, ValueError, ImportError) as e:
nagios_exit(NAGIOS_UNKNOWN,'temperature sensor read failed: %s' % e)
elapse = endtime-starttime
--
libgit2 0.22.2