Team 26 - Electronics and Software

Electronics:

A circuit diagram of the electronics used in this project is shown below:

The major components include our Arduino Uno microcontroller, motor with associated driver, external power supply, force-sensing resistors, and various buttons and other controls to operate the system. 

We used a push button to switch between the two control modes of the system (human-operated or autonomous using force-based positional control), a potentiometer to vary the direction of the motor speed when manually operating, a LED to display desired colors associated with the current mode of the gripper, and two force-sensing resistors to roughly measure the force applied to the grasped object. These inputs were taken in by the logic on our Arduino and used to produce updates in the direction and step size commands sent to our stepper motor driver and executed by the motor itself. Details of the specific parts used in this project can be found on the Bill of Materials page in the Appendix.

Here is a diagram of the circuit used to power the gripper and images of the circuit built on the physical prototype:

Software:

For this project, we used primarily the MATLAB programming environment and VSCode’s PlatformIO extension to write our kinematics and Arduino code, respectively. 

The MATLAB code was split into two functions that each derived the position and velocity kinematics of one of the two sub-mechanisms, then were combined together using known offsets between inputs and other variable relations. This code is shown in the Appendix.

The main code uploaded to the Arduino is also shown in the Appendix. For the full code, users are directed to this project’s GitHub repository.