As Desk Buddy will be displaying various messages throughout the day for both the owner and the visitor it may be useful to navigate back to an older message.

Using the principle of identifying a solution looking for a problem, the APDS-9960 Gesture Sensor board presented itself as an interesting way to interact with the device for visitors. The mobile app should allow for the owner to view a timeline of messages displayed by Desk Buddy.

The visitor would use hand gestures in front of the 9660 to "swipe left" or "swipe right" between messages in the timeline. A "near" gesture may trigger a menu that could allow for the user to perform certain functions such as "Say hello to owner".

The 9660 includes an I2C interface and an interrupt pin. As the 9660 I2C interface supports 3.3V it can be connected directly to the SDA (D4) and SCL (D5) pins on the NodeMCU. I2C is a bus based communication that allows for multiple devices to be connected to the same lines. Each device has an address that is used to tell the device when to "latch" on to the SDA line.

SparkFun provides an Arduino library that was modified by Jonathan Ulmer to work with the ESP8266.

More to come.