Arduino++
The MPS020N0040D pressure sensor is a cheap component readily available for purchase on sites like eBay.
I recently needed to create a blow activated switch and, as I already had a few of these at hand, decided to design a minimal circuit that would provide a digital output when a threshold pressure was detected by the sensor.
The LM3x series of sensors are precision, easily-calibrated, integrated circuit temperature sensors. These are ideal as a beginner sensor, only to disappoint when code is copied from somewhere, run on the MCU and the temperature readings seem to be wildly varying and incorrect. Why is this happening and what can be done about it? Read on.
The TCS230 (and equivalent TCS3200) sensor can be easily purchased mounted on any number of inexpensive breakout boards, similar in design to that shown in the photo. These boards extend the package connections to header pins, and integrate LEDs for illumination of the target object. These sensors work well to recognize color but they need to be calibrated. An Arduino library for this sensor can be found at my Arduino Library site and elsewhere.
Arduino++ 