Raspberry Pi Zero W Scripts

Scripts created for Raspberry Pi Zero W assistant using Google Assistant and Google Cloud SDK. Root folder ./ contains scrips written for features listed below, ./drivers folder contains drivers written for external hardware connected through GPIO pins.

Prerequisite

• Python3 with libraries: python3-gpiozero, redis, python-nmap, tcp-latency
• Google Assistant SDK
• Redis
• OMX Player or mpg123
• nmap

Scripts

Initial setup

Set scripts folder (this) in path environment variable /home/pi/.profile:

# set PI_HOME
export PI_HOME="/home/pi"

# set PATH to custom scripts folder if it exists
if [ -d "$PI_HOME/scripts" ] ; then
    export SCRIPTS="$PI_HOME/scripts"
    PATH="$PI_HOME/scripts:$PATH"
fi

# set PATH to custom drivers folder if it exists
if [ -d "$PI_HOME/scripts/drivers" ] ; then
    export DRIVERS="$SCRIPTS/drivers"
    PATH="$PI_HOME/scripts/drivers:$PATH"
fi

speak

Uses google cloud text to speech api to create mp3 speech files. Requires omxplayer (or mpg123) and gcloud cli (https://cloud.google.com/sdk/docs#deb)to be installed. Refer https://cloud.google.com/text-to-speech/docs/quickstart-protocol for tutorial Usage: aehe-speak <setup|add|speak> [key] [text]

# Setup speak (one time)
bash speak.sh install
# Create mp3 file from key and text
bash speak.sh add SAY_HELLO "Hello! This is Raspberry Pi Zero W"
# Play mp3 file for the key
bash speak.sh say SAY_HELLO

internet_indicator.sh

This script pings 8.8.8.8 to check internet and sets GPIO(4) output 1 if internet connection is not available else will set it 0 Usage: sudo bash internet_indecator.sh <start|check>

Setup crontab to schedule the script

• Edit corntab config: crontab -e
• Configure start script on boot @reboot sudo bash /home/pi/scripts/internet_indicator.sh start >/dev/null 2>&1
• Configure check script every minute * * * * * sudo bash /home/pi/scripts/internet_indicator.sh check >/dev/null 2>&1 Due to limitations of crontab above line schedules check per minute, to check every 20 seconds you can do

* * * * * sudo bash /home/pi/scripts/internet_indicator.sh check >/dev/null 2>&1
* * * * * sleep 20; sudo bash /home/pi/scripts/internet_indicator.sh check >/dev/null 2>&1
* * * * * sleep 40; sudo bash /home/pi/scripts/internet_indicator.sh check >/dev/null 2>&1

display_stats.py

Prints hardware stats like temperature, pressure, humidity, cpu, memory, disk, time, network on screen. Usage python3 display_stats.py argument Valid arguments are:

-d      : Displays date and time, arg2 decides time interval to refresh seconds
-n      : Displays network stats
-t      : Displays temperature from sensor and weather api
-p      : Displays pressure from sensor and calculates sea level pressure
-h      : Displays humidity from sensor and weather api
-c      : Displays cpu usage and cpu temperature
-m      : Displays memory and disk usage
-l      : Displays ambient light, sunset / sunrise time
-sn     : Scans the network using nmap
-sw     : Calls weather api for current location

Example:

python3 display_stats.py -d 7
python3 display_stats.py -n

Setup crontab to schedule the information to be displayed

• Edit corntab config: crontab -e

@reboot sudo /usr/bin/python3 /home/pi/scripts/drivers/lcd_16x2.py -i >/dev/null 2>&1
@reboot sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -sn >/dev/null 2>&1
@reboot sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -sw >/dev/null 2>&1
* * * * * sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -n >/dev/null 2>&1
* * * * * sleep 7.5; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -t >/dev/null 2>&1
* * * * * sleep 15; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -p >/dev/null 2>&1
* * * * * sleep 22.5; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -h >/dev/null 2>&1
* * * * * sleep 30; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -c >/dev/null 2>&1
* * * * * sleep 37.5; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -m >/dev/null 2>&1
* * * * * sleep 45; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -l >/dev/null 2>&1
* * * * * sleep 52.5; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -d 7 >/dev/null 2>&1
*/5 * * * * sleep 11; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -sn >/dev/null 2>&1
*/15 * * * * sleep 47; sudo /usr/bin/python3 /home/pi/scripts/display_stats.py -sw >/dev/null 2>&1
37 */4 * * * sleep 19; sudo /usr/bin/python3 /home/pi/scripts/drivers/lcd_16x2.py -i >/dev/null 2>&1

Drivers

bme280.py

Assuming the python script is executed from root./folder

from drivers.bme280 import readBME280All
# returns tuple (temperature, pressure, humidity)
readBME280All()

pwm_op.py

Creates pulse width modulation of 120Hz with duty cycle of 0.6 on GPIO 27 Create service to start execution on startup

sudo nano /lib/systemd/system/pwm_op.service 

Add below contents

[Unit] 
Description=Create 120Hz 0.6 duty cycle pulse width modulation output 
After=multi-user.target 
 
[Service] 
Type=idle 
ExecStart=/usr/bin/python3 /home/pi/scripts/drivers/pwm_op.py 
 
[Install] 
WantedBy=multi-user.target 

Configure systemd

sudo systemctl daemon-reload 
sudo systemctl enable pwm_op.service 

led_gpio.sh

Driver to set color leds on/off

Setup crontab to initialize LED GPIO at startup

• Edit corntab config: crontab -e

@reboot sudo /bin/bash /home/pi/scripts/drivers/led_gpio.sh init >/dev/null 2>&1

Supported colors are red, green, blue, white and supported states are 0, 1 Example: led_gpio.sh set red 1

spi.sh

Driver to read values from SPI input and handle value changes. CE0 port is connected to MCP3008 of which CH0 is mode select potentiometer and CH1 is TEMT6000 output. Create service to start execution on startup

sudo nano /lib/systemd/system/spi.service 

Add below contents

[Unit] 
Description=Service to read SPI inputs on CE0
After=multi-user.target 
 
[Service] 
Type=idle 
ExecStart=/usr/bin/python3 /home/pi/scripts/drivers/spi.py 
 
[Install] 
WantedBy=multi-user.target 

Configure systemd

sudo systemctl daemon-reload 
sudo systemctl enable spi.service