Trip to República del Salvador Street.

Last Tuesday we went to a street on the center of our capital city called República del Salvador in order to search for sensors for determining the angular position of the base motor and the pendulum. First se seek for some kind of potentiometer like the posted below or another one that can take infinite turns and make an specific reading on a particular angular position. But on any little store we asked for it they didn't have anything like it, the closest things they had was a precision potentiometer that had 10 turns but had different resistive values con each part of the 10 turns.

Then we decided to look for an encoder, but almost anybody had one. We encountered a place where repaired CD and DVD readers and they showed us the encoders they had, but the problem was that they were designed to suit a DVD reader and the circuit that read the encoder was part of an entire solution for many tasks. Also we had the option to use only the sensor and the wheel but the sensor didn't have any code number so it could be a hard task to find the way to understand the encoder.

Finally as the price of the encoder was very expensive and we had little time till down we decided to buy two precision potentiometers.

We hope they will be enough to sense the rotatory movement of the motor and the pendulum, nonetheless we will still try to find an encoder.