- Ambient Temperature and Humidity
- Ambient Pressure
- Multi-gas sensor
- Lightning sensor
- X-ray and Gamma Ray Detector
- Low-resolution thermal camera
- Home-built linear polarimeter
The iPhone and subsequent smartphones changed all that. Apple put a magnetometer, gyroscope, accelerometer, microphone and camera into the iPhone, partly to support its unique functionality (such as automatically detecting when the phone was rotated and switching into portrait or landscape mode,) and partly to replicate the functionality of existing feature phones. However, once those sensors became widely available to consumers, developers figured out new ways to use them. In addition to the myriad of camera apps, there are several apps that use smartphone cameras to detect the user's pulse rate. Some apps turn smartphones into fitness or sleep trackers. Phone cameras are being used for light metering apps for still photography and video. The combination of motion sensors and touch screen is being used for game input, replacing joysticks, button pads and steering wheels.
As smartphone sales increased, the cost of making sensors, and the prices of the sensors, declined. That made other sensor applications, such as the many fitness trackers now on the market, practical. Now, as with the Arducorder Mini, we're starting to see sensors that were primarily used for industrial and scientific applications drop in price and size to the point where they're practical to use for consumer applications. And, as we saw with smartphone sensors, developers will come up with new, innovative applications for this new generation of sensors, from home security to low-cost field blood testers.
Sensors are expanding from a niche business to core technology for many products and markets, and as the markets for sensors grow, more and more types of sensors will become available at mass market prices. That virtuous cycle will benefit app developers, hardware vendors and sensor manufacturers, as well as consumers and businesses.