We created an internet of things project that has two way communication between Particle Argons. These two argons will notify the user when a safe or lockbox has been opened. This is done using a IFTTT app, Groupme and Thingspeak. One of the argons has a photoresistor that monitors the light level. The other argon is used to communicate with IFTTT to send a notification to Groupme. One of the argons will also send data to a chart in Thingspeak.
This project uses a photoresistor to constantly monitor the light level of a point of interest. The Argon in the point of interest is programmed to take an analog reading of the pin connected to the photoresistor and publish that value to Thingspeak so that a chart can be made of light level readings over time. The read value is then compared to a preset threshold value in an IF statement to determine if the door has been opened. If this is true, the Argon publishes an event titled "lightlevelchanged49" which is recieved by Argon 2 in a subscibe function. Argon 2 will then send a text via Groupme saying that the door has been opened. After this, the Argon will publish another event titled "subscription_received49" and blink its D7 LED until Argon 1 has detected that the door is closed. Particle 1
Thingspeak channel: https://thingspeak.com/channels/912527