BeagleBone Web Server - Temperature Sensor

RE: BeagleBone Web Server - Temperature Sensor

Former Member — Tue, 04 Aug 2015 02:28:41 GMT

i like it.... would you tell me how to use DHT11 humidity sensor instead of MCP9701E.... ??

RE: BeagleBone Web Server - Temperature Sensor

Former Member — Wed, 23 Jul 2014 06:40:26 GMT

what if i want to use temp. sensor of LM35DZ?

i just changing MCP9701E.cpp file name to LM35DZ.cpp?

RE: BeagleBone Web Server - Temperature Sensor

Former Member — Sun, 29 Dec 2013 11:34:50 GMT

Hello,

This is for BBB and Ubuntu:

-I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

also path to AIN1 in tempmeas.cpp:

// Initialize the temperature sensor

MCP9701E sensor("/sys/devices/ocp.2/helper.14/AIN1");

g++ tempmeas_initial.cpp -o tempmeas_initial -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

g++ tempmeas.cpp MCP9701E.cpp -o tempmeas -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

or like this:

g++ tempmeas.cpp MCP9701E.cpp -o tempmeas `mysql_config --cflags --libs`

check adafruit for BBIO library:

Using the Adafruit_BBIO Library | Setting up IO Python Library on BeagleBone Black | Adafruit Learning System

I'm using TMP 36 analog temperature sensor; here is nice tutorial on adafruit:

Overview | Measuring Temperature with a BeagleBone Black | Adafruit Learning System

I modified python script so it will insert data in TempDB database, so basically this scrip will replace tempmeas:

temp.py:

#!/usr/bin/env python

import time

import MySQLdb

import Adafruit_BBIO.ADC as ADC

# Sensor

sensor_pin = 'P9_40'

# Setup

ADC.setup()

while True:

reading = ADC.read(sensor_pin)

millivolts = reading * 1800 # 1.8V reference = 1800 mV

temp_c = (millivolts - 500) / 10

now = time.strftime("%Y-%m-%d" " " "%X")

db = MySQLdb.connect(host="127.0.0.1",user="bone",passwd="bone",db="TempDB")

cur=db.cursor()

sql="INSERT INTO TempMeas (MeasTime, Temp) VALUES ('%s', '%s')"

cur.execute(sql % (now, temp_c))

db.commit()

db.close()

time.sleep(60)

To run script use: python temp.py, and put it in cron so it will run on startup.

Also you can add: <meta http-equiv="refresh" content="60" > inside head tag in temp.php so it will auto refresh every 60 seconds.

Thanks again for this tutorial, really like it..

RE: BeagleBone Web Server - Temperature Sensor

Former Member — Sat, 28 Dec 2013 01:40:31 GMT

I'm new to Linux and the BeagleBone Black, and your tutorials have helped me get up and running with the BBB much more quickly. Thanks a ton. I did run in to several issues on the way that were huge headaches for me until I figured them out. The biggest thing I ran into in this part was compiling. For some reason I could not get it to compile the way you did. I had to compile the objects individually first to get it to work. This is what I did:

g++ -c MCP9701E.cpp

g++ -c tempmeas.cpp -I/usr/include/mysql -lmysqlclient

g++ -o tempmeas tempmeas.o MCP9701E.o -I/usr/include/mysql -lmysqlclient

I have no idea why I had to do this.

RE: BeagleBone Web Server - Temperature Sensor

Former Member — Sun, 22 Dec 2013 18:48:47 GMT

great tutorial..

RE: BeagleBone Web Server - Temperature Sensor

DAB — Sun, 24 Nov 2013 21:37:08 GMT

Hi Shawn,

Thanks for your excellent example. I have added this to my list of things to do, but right now my queue is over loaded, so it might take some time before I can try this myself.

DAB