This week, I’ve put the whole system together with the Arduino. On Sunday, I ran into some connectivity issues with the FPGA and the IMU, but had successfully gotten all the motors running simultaneously with the new logic level shifters. The connectivity issues with the IMU seemed to stem from unstable wire connections, as it would connect and run for a bit, but then lose the connection and not be able to communicate with the device. When running a program just to read from the IMU, it runs well. But when running a program to activate the linear actuators, while reading from the IMU; it loses connection.
After Sunday, we decided to get the whole system running with the Arduino. I created a few different programs just to test the functionality of the motors, all connected together. First, to test whether all of the motors ran, I ran a script where I could run the wheels forwards/backwards, and the linear actuators up/down. I ran into some issues with this because there were some issues with the motor drivers again. But after we diagnosed the issues and replaced some of the motor drivers, we went to drive the linear actuators based on the angle of the IMU. Then I created a short run that would stop after two seconds of the robot trying to climb up the ramp. The runs were not very good because the ramp had a large lip, and I needed to run the robot pretty quickly, so the linear actuators had trouble adjusting in time. As Sara was able to smooth out the lip, I was able to run a program that incremented the duty cycle of the motors until it could get over the lip. This ensured that the robot used a minimal speed to get over the ramp, so this gave the linear actuators the best chance to adjust in time.
https://drive.google.com/file/d/1VAoIBAHETLK4q6Kjd93y6QgunjlTJPVh/view?usp=drive_link
Our schedule is behind. We want to conduct some more testing on different angles and actually get some water in the cup so that we can know how much angle we can accomodate before spilling the water. If the professor feels that this progress is good enough, I also want to replace the Arduino with the FPGA. Once I am able to debug why the IMU and FPGA have connectivity issues for certain programs, it will be at similar progress as the Arduino.
The deliverables for the next week are to test on higher angles. I think it would be beneficial to slow the robot down more, after the first set of wheels get over the lip. Then once the back wheels struggle to get over the lip again, we would continue to increment the duty cycle. This would give the linear actuators the most time to adjust its angle. Also swapping from Arduino to FPGA would also be a deliverable for the next week.
Questions for the week:
As you’ve designed, implemented and debugged your project, what new tools or new knowledge did you find it necessary to learn to be able to accomplish these tasks? What learning strategies did you use to acquire this new knowledge?
As I was learning how to use the FPGA for the project, I read a lot of different projects on Hackster for how to drive wheels with an FPGA. I also read a few different article on how to use SPI and I2C with the FPGA on Hackster. My learning stategies were just to read different ways to solve the problem so that I had a better understanding, so that I could apply the concepts to our own project. Working through the project, I also did some circuit debugging that I haven’t done since 18-100. I think it was beneficial to go through the steps to diagnose problems and isolate potential issues. Reading the documentation to know that certain voltage levels don’t work and Googling how to solve those issues was another strategy. Watching Youtube videos on FPGA projects that did similar things, also aided in the project. The Arduino portion of the project, I just worked through it as the documentation is very clear and the integration is seamless.