Light Sensor

CSC 453 HW #1. I was in charge of the code for Device A which sampled the LDR and potentiometer values. I needed to use an ADC to retrieve the potentiometer values & after much research I ended up going with the MCP3008 as opposed to the ADS1115.

Broker Readme

Author: Carter Thunes, Laptop #1/Broker

• The computer runs Mosquitto locally & acts as the MQTT broker server. It handles all messages from the clients and then routes the messages to the appropriate destination clients.

• Prerequisites & Dependencies: Mosquitto from their website, update config file for broker to CSC 453 requirements, and stored in \mosquitto folder, port forward port 1883 on broker's router to host that broker is run on, & disable any firewalls for things coming from port 1883. To run: on cmd navigate to folder where mosquitto was installed ('cd c:\Program Files\mosquitto'):

  mosquitto -v -c csc453.conf
  

Device A Readme

Author: Soumya Gade, Raspberry Pi A

• Device A samples LDR and potentiometer values every 100 ms. It publishes these to the broker after normalizing the raw values to be between 0 and 1. Device A subscribes to lightSensor and threshold upon connecting to the broker. On keyboard interrupt, Device A will perform GPIO cleanup & exit.

• Prerequisites & Dependencies: Raspberry Pi set up as described in the Raspberry Pi A Schematics Diagram, Python 3, Python installation of MCP3xxx Library, Paho MQTT client (install: pip install paho-mqtt). To run:

  python3 device_a.py
  

  

Device B Readme

Author: Mason Rowland, Raspberry Pi B

• Device B code controls the activation of LEDs 1-3, in each specific case:

  • LED 1 will activate when the mqtt topic "LightStatus" receives message "TurnOn"
  • LED 1 will deactivate when the mqtt topic "LightStatus" receives message "TurnOff"
  • LED 2 will activate when the mqtt topic "Status/RaspberryPiA" receives message "online"
  • LED 2 will deactivate when the mqtt topic "Status/RaspberryPiA" receives message "offline"
  • LED 3 will activate when the mqtt topic "Status/RaspberryPiC" receives message "online"
  • LED 3 will deactivate when the mqtt topic "Status/RaspberryPiC" receives message "offline"

• Device B subscribes to all three of these topics upon connecting to the broker. On Keyboard Interrupt, Device B will turn off all LEDs, perform GPIO cleanup, and exit.

• Prerequisites & Dependencies: Raspberry Pi set up as described in the Raspberry Pi B Schematics Diagram, Python 3, Paho MQTT client (install: pip install paho-mqtt). To run:

  python3 device_b.py
  

  

Device C Readme

Author: Nick Richardson, Raspberry Pi C

• Device C subscribes to "lightSensor", "threshold", and a special development test channel: "dev/test". The received lightSensor and threshold values are compared and the lightStatus is updated based on the value. If the light status is changed, this is reported to the broker on the channel: "LightStatus".

• Endpoints: Nick (Device C) host is 192.168.1.153 and port is 1883.

• Prerequisites & Dependencies: Python 3, Paho MQTT client (install: pip install paho-mqtt). To run:

  python3 device_c.py
  

Laptop #2 Readme

Author: Carter Thunes, Laptop #2

• Laptop #2 subscribes to all of the following topics upon connecting to the broker: lightSensor, threshold, LightStatus, Status/RaspberryPiA, Status/RaspberryPiC. Laptop #2 has an additional .py that only subscribes to lightStatus. It then prints the topics and their messages along with a timestamp. No duplicate messages from the broker will be displayed.

• Prerequisites & Dependencies: Python 3, Paho MQTT client (install: pip install paho-mqtt). To run: navigate to folder where files are saved in cmd ('cd Documents\CSC453'):

  py laptop_2.py > output.txt
  py laptop_2_led_1.py > outputled.txt