powerpi

This Raspberry Pi prepaid energy monitor takes a photo of the amount of money you have left and emails it to you at a predefined time via a cronjob.

Requirements

• Raspberry Pi (any)
• Raspberry Pi camera module (any)
• Enabled camera module. Run: sudo raspi-config to enable, then reboot
• Raspberry Pi Wi-Fi Dongle (if using a Raspberry Pi < 3)

Package dependencies

• raspistill
• ssmtp
• mailutils
• mpack

Install

Clone to the ~/powerpi directory on your Raspberry Pi

git clone git@github.com:n8kowald/powerpi.git ~/powerpi

Install ssmtp and mailutils

sudo apt-get install ssmtp
sudo apt-get install mailutils

SSMTP settings

Edit your SSMTP config

sudo vim /etc/ssmtp/ssmtp.conf

Add or update the following settings

root=postmaster
mailhub=smtp.gmail.com:587
rewriteDomain=gmail.com
FromLineOverride=YES
UseSTARTTLS=YES
# Replace with your Gmail username
AuthUser=user@gmail.com
# Allow less secure apps to access your account: https://support.google.com/accounts/answer/6010255
# Replace with your application specific password: https://support.google.com/mail/answer/185833
AuthPass=

Send a test email using your settings (replace user below)

echo "This is the body" | mail -s "Subject" user@gmail.com

SSMTP docs (including how to secure it): https://wiki.archlinux.org/index.php/SSMTP

Install mpack

sudo apt-get install mpack

Make shell script executable

sudo chmod +x ~/powerpi/powerpi.sh

Create the cronjob

Edit your crontab by typing crontab -e and paste the following command

# Run daily at 20:00 - change the time here: http://crontab-generator.org
0 20 * * * /home/pi/powerpi/powerpi.sh >/dev/null 2>/dev/null

Configure

• Edit ~/powerpi/powerpi.sh and replace RECIPIENTS="user@gmail.com" with your email address
• Play with the settings passed to 'raspistill' to get the best photo for YOUR light conditions

raspistill --exposure night --vflip --hflip --width 650 --height 450 --timeout 7000 --brightness 57 --sharpness 75 --output "${DIR}${FILENAME}"

See the full list of options by typing raspistill

Alias (optional)

Run this script by typing 'powerpi', or change the alias name.

# Edit your ~/.bashrc
vim ~/.bashrc

# Paste the following to run the script on demand
alias powerpi='sh /home/pi/powerpi/powerpi.sh'