Page 118 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

Humidity
Passive resistive humidity sensors are a relatively new product
that can be purchased.
Testing sensors
When designing and building sensor systems, it’s a good idea to test
them before committing to use the system on a robot. One method
that I used was to build a small mobile robot whose only function is
to test sensors. That way reliability and response time can be deter-
mined before committing the sensors on a more elaborate robot.
The robot can test bump switches, light switches, bend sensors,
and infrared and ultrasonic obstacle avoidance sensors. Other
types of sensors may require a different test bed.

Building a tester robot

Tester is the name I’ve given this small robot. The foundation of
the robot is a small electric car that can be purchased for less than
$10.00 (see Fig. 5.47).
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The schematic for Tester is shown in Fig. 5.48. The sensor con-
nects to the trigger input of a 555 timer set up as a monostable

5.47 Tester
Team LRN Sensors