Enttoi Raspberry Pi client

Branch	Travis
master
dev

This is a client application that runs on RPi and streams sensors data to gateway.

The client will read each sensor's state every X ms. After reading, it will report on each change of state immediately or at least once every Y seconds (even if the state wasn't changed) to the gateway. This will provide an efficient way of getting real-time state of sensors and track of online/offline clients (due to network or other issues).

For each sensor a separated thread is spinned, so the IO operations won't block reporting of different sensors.

Board schematic

The following parts required:

• Raspberry Pi board
• WiFi dongle (optional if there is LAN socket)
• If the WiFi dongle used at least 2A power adapter is required.
• Breadboard (optional)
• One LED connected to wPi=0 or BCM=17 pin. The LED has 4 states:
  • On - client launched, but no request is sent to gateway
  • Slow blinking - latest request were successfull
  • Fast blinking - latest request wasn't sent due error (timeout, network errors, etc)
  • Off - client terminated
• 2 reed switches connected to wPi=5,7 or BCM=4,24.

All parts should be connected in the following way:

Application Configurations

The only prerequisite is to have environment variables which defines the endpoint of API and a security token.

Those can be defined either simply in /etc/environment:

ENTTOI_ENDPOINT="[gateway endpoint URI]"
ENTTOI_CLIENT_TOKEN="[client's token]"

Running as shell application

Since GPIO requires elevations, environment variables needs to be added for sudo

sudo visudo

then add:

Defaults	env_keep +="ENTTOI_ENDPOINT"
Defaults	env_keep +="ENTTOI_CLIENT_TOKEN"

Deploy the / folder into Raspberry Pi and start client from terminal:

sudo python app.py

Running as daemon service

The client daemonized using Stephen's fairly painless trick.

Assuming that the project cloned into /home/pi/enttoi-client (this can me changed in enttoi.sh), copy init script to /etc/init.d:

sudo cp enttoi.sh /etc/init.d

Make sure that both enttoi.sh and service.py are executable:

sudo chmod 755 /etc/init.d/enttoi.sh
chmod 755 service.py

At this stage you can start and stop service:

sudo /etc/init.d/enttoi.sh start
sudo /etc/init.d/enttoi.sh status
sudo /etc/init.d/enttoi.sh stop

See log file at /tmp/entoi-client.log for info or errors.

Now, add it to boot sequence:

sudo update-rc.d enttoi.sh defaults