DIY optical rotary encoder for geared motors

One of the most important things in robotics is to accurately sense and control the rotation of a motor. One way to do this is to use stepper motors but they’re bulky, have very less torque and speed. Another is to buy a motor with quad encoders which work on the basis of hall effect, they give a very high resolution of about 10000-20000 counts/rotation but they’re very expensive. In this tutorial I’m going to show you how to build a very simple attachment to any geared motor to measure the angular rotation

Configuring and using XBEE wireless modules

Xbees are some of the most powerful wireless modules you can find and they’re also very easy to configure and use. The only thing is they cost about Rs.1000 to Rs.2500 depending on the range and other parameters. If you’re like me and only bought the modules