Home Automation with Raspberry Pi: Difference between revisions
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=== Set up 1-wire === | === Set up 1-wire === | ||
[[File:RaspberryPiDHT11.png]] | |||
=== Set up camera === | === Set up camera === | ||
[[Category:RaspberryPi]] | [[Category:RaspberryPi]] |
Revision as of 12:44, 6 December 2018
The Why Of Fry
I moved to a house and would like to monitor and automate some things:
- log room temperatures
- log outside temperature
- tbd
Preparation
Parts list
- Raspberry Pi (I formerly used this Rev 2 for http://www.wurst-wasser.net/wiki/index.php/Tomat-O-Mat - I have a garden now and don’t need it anymore)
- Power supply for the Pi
- DHT11 (side project RaspberryPi Humidity and Temperature Sensor)
- DS18B20 (side project RaspberryPi Temperature Sensor)
- some resistors, cables, wires, boards, and the usual soldering equipment
Setting up the Pi
Since the Pi was running Debian Wheezy (which is AFAIK obsolete) I decided to install Raspbian Stretch.
- Download it here: https://www.raspberrypi.org/downloads/
I skipped NOOBS and did the installation myself (with help from https://www.raspberrypi.org/documentation/installation/installing-images/README.md and https://www.raspberrypi.org/documentation/installation/installing-images/mac.md ):
# diskutil list […] /dev/disk5 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *15.8 GB disk5 1: Windows_FAT_32 58.7 MB disk5s1 2: Linux 15.8 GB disk5s2 # diskutil unmountDisk /dev/disk5 Unmount of all volumes on disk5 was successful # dd bs=1m if=2018-11-13-raspbian-stretch-full.img of=/dev/rdisk5 conv=sync 5052+0 records in 5052+0 records out 5297405952 bytes transferred in 486.102151 secs (10897722 bytes/sec) # diskutil eject /dev/rdisk5 Disk /dev/rdisk5 ejected #
After that, enable interfaces (ssh, camera port or 1-wire) as needed.
Update the Software
Use the graphical interface or some CLI (apt) tool. Setting up WiFi might help :)
Install Tools
# dpkg --configure -a # apt-get install locate # apt-get install gnuplot # apt-get install git
Since there seems to be no kernel module for DHT11, do this:
Installing DHT11 driver
# cd /home/pi/bin # git clone git://git.drogon.net/wiringPi # cd wiringPi/ # git pull origin # ./build
Create a file hum_temp3.c with this content (Code taken from here (Rahul Kar) and here):
/* from http://www.circuitbasics.com/how-to-set-up-the-dht11-humidity-sensor-on-the-raspberry-pi/ Based on hum_temp2.c. Reads data until it gets a valid set. Then prints it once. */ #include <wiringPi.h> #include <stdio.h> #include <stdlib.h> #include <stdint.h> #define MAXTIMINGS 85 #define DHTPIN 7 int dht11_dat[5] = { 0, 0, 0, 0, 0 }; int read_dht11_dat(char *message) { uint8_t laststate = HIGH; uint8_t counter = 0; uint8_t j = 0, i; float f; int err=0; dht11_dat[0] = dht11_dat[1] = dht11_dat[2] = dht11_dat[3] = dht11_dat[4] = 0; pinMode( DHTPIN, OUTPUT ); digitalWrite( DHTPIN, LOW ); delay( 18 ); digitalWrite( DHTPIN, HIGH ); delayMicroseconds( 40 ); pinMode( DHTPIN, INPUT ); for ( i = 0; i < MAXTIMINGS; i++ ) { counter = 0; while ( digitalRead( DHTPIN ) == laststate ) { counter++; delayMicroseconds( 1 ); if ( counter == 255 ) { break; } } laststate = digitalRead( DHTPIN ); if ( counter == 255 ) break; if ( (i >= 4) && (i % 2 == 0) ) { dht11_dat[j / 8] <<= 1; if ( counter > 16 ) dht11_dat[j / 8] |= 1; j++; } } if ( (j >= 40) && (dht11_dat[4] == ( (dht11_dat[0] + dht11_dat[1] + dht11_dat[2] + dht11_dat[3]) & 0xFF) ) ) { f = dht11_dat[2] * 9. / 5. + 32; sprintf(message, "Humidity: %d.%d%%, Temperature: %d.%dC (%.1fF)\n", dht11_dat[0], dht11_dat[1], dht11_dat[2], dht11_dat[3], f ); err=0; } else { sprintf(message, "Data not good, skip\n" ); err=1; } return (err); } int main( void ) { //printf( "Raspberry Pi wiringPi DHT11 Temperature test program\n" ); if ( wiringPiSetup() == -1 ) exit( 1 ); char message[1024]; int error=1; int tries=0; while ( error!=0 && tries < 42 ) { tries++; error=read_dht11_dat(message); delay( 1000 ); } if (error == 0) { printf(message); } else { printf("Failed to read data (%i tries)", tries); } return(0); }
Compile it:
# gcc -o sensor3 hum_temp3.c -L/usr/local/lib -lwiringPi
Test it:
./sensor3 Humidity: 35.0%, Temperature: 22.0C (71.6F)
Set up your shell language
I strongly recommend keeping your shell (or complete OS) in english.