One of the aspects of any tinkerer's (and mine) activities that goes largely overlooked is learning about, sourcing and trying out new electronic parts. The industry continuously churns out sensors and microcontrollers that can do more than the previous generations. It's up to you to get acquanted with as much of the fresh stuff as possible, if you want to stay on the bleeding edge.
Step 1: Proximity Sensing As I Knew It
Having been involved in robotics in my university years, I've always looked out for new solutions to the hottest hardware problems in this field. One of such challenges was accurate proximity sensing - the ability to accurately sense distance to other objects was often what separated winning robots from the rest in robotics contests.
The type of sensor we (and the majority) used back then was a common ultrasonic one, mostly due to its low cost and ubiquity. You know, something like the one I attached below - HC-SR04.
This sensor continuosly sends click train in ultrasound, senses the
reflections of those clicks. By measuring the time it took for the click to bounce back, we can tell the distance to the nearest object.
It was simple to use them,but there were two downsides that became apparent with time:
* Detection range of 2cm to 400 cm (1" - 13 feet) seems huge, and it is. What's inconvenient is that when something approaches closer that 2cm, sensor starts spouting erratic distances.
* Doesn't work well with acoustic absorbers (e.g. cloth, foam).
Step 2: Gesture and Color Sensing As I Knew It
To be fair, I never stumbled upon popular and inexpensive sensors for these purposes, so frankly I knew precisely squat.
Step 3: APDS-9960 - Gesture, Proximity, Ambient Light and RGB Sensor
When I learned about this sensor, it sounded too good to be real.
Gesture sensing (up, down, left, right, up, down, in and out), proximity sensing, color and ambient light sensing - looks like another indispensable part in maker's cabinet!
No doubt it can do all these things, but can it do them WELL? My expectation was that it would be good at close range and with acoustic absorbers too, being used as a complement to ultrasonic sensor to form a universal proximity sensing solution, thus eliminating the shortcomings of both sensor types. According to the specs, though, the proximity sensing capabilities on this one turned out to be almost useless. 10 to 20cm (4" - 8")? Pfft...
Still, APDS-9960 looked promising, so I got myself a breakout board.
Step 4: Results, Know-hows Etc...
Results of my look into the sensor usage plus one cool trick I use to improve color sensing on this sensor can be found in the link below:
I even filmed a tiny video where I show off its practical usage (also included in the link).
You've reached the end of this Instructable. Leave your suggestions in the comments! What new sensors you'd like to see reviewed?