Phidgets and other places to look for low-cost sensor modules for mbed projects

27 Aug 2010 . Edited: 16 Sep 2010

Phidgets makes a nice variety of low-cost sensor modules (IR and Sonar distance, force, pressure, temp, touch, humidity, motion, current, PH, etc). They are designed to plug into their digital and analog USB I/O modules, but they can also work well for many mbed projects. I had several around from some earlier projects and have interfaced a few of them to mbed. I was just using the sonar and IR distance ones. Robot Electronics, Sparkfun, Acroname, Lynxmotion, Robotics Connection, SKpang, and Pololu also have many of the sensors and other parts often used in robotics projects.

The small Phidget sensor modules run off of 5V or some down to 3.3V and many have an analog output. The analog sensors are mounted on small PCBs with a three wire connector just like an RC servo. Pins are Vcc, GND and analog out. So no soldering or surface mount adapter board is needed and you can stick a jumper wire in the connector and plug the other end into a protoboard. In some cases you might need to scale the sensor's "analog out" from 5V down to 3.3V before connecting it to an mbed "analog in" pin. A few have digital outputs or include a USB interface, so double check the detailed description. When you see "ratiometric" or "non-ratiometric" in the short description that means analog output from the sensor. They also have a couple of small relay and SSR boards with small screw terminals for wires that might come in handy in addition to motors and servos.

http://www.phidgets.com/products.php?category=1 is a link to the Phidgets sensor catalog page or http://www.active-robots.com/products/phidgets/sensors-phidgets.shtml in UK.

Here are images of some of the analog sensor boards and the sensor interface cable: