Problem Encountered

In the combining everthing that we discussed in previous posts, there are some features was modified or eliminated as we encountered some problems. There are two features that we modified which are radio frequency module (RF) and encoder.

The radio frequency signal is totally eliminated from our design. We are using wire cables instead of wireless. The reasons we eliminate the feature is the signal in the RF is interphasing with the other group frequency. Most of the other groups are using the same model of RF with the same frequency (433MHz). Distortion of information produced and consequently the data received or transmitted is not the acquired signal. In the design, the functionality of RF is very important. If the RF is not working properly, the design will become a big failure. Another reasons we give up for RF is protocol. The pre-set method to transmitter and receiver cannot applied in the our control car because the value of speed changing time by time. Therefore, the probability the receiver receive the wrong data is very high. As we discussed among the team members, we are not willing to take any risk, so we change the RF to the wire cables. Furthermore, the main purpose of the project is to build test board to stepper motor.

The second feature that we modified is the encoder, speed calculation. As we proposed, the encoder should detect the speed of the stepper motor. Unfortunately, the encoder that we are using was broke during the installation part. Because of time limiting factor, we modified the calculation speed mechanism. Microcontroller itself calculates the rotation of the stepper motor. Data collected from the test done in lab to come out with speed and torque equation. This equation is programmed in the microcontroller. Referring to this equation, the speed calculated.