Team A6: Mario Kar – Gesture-Controlled RC Kart
Carnegie Mellon ECE Capstone, Fall 2025 | Caitlyn Fong, Enrique Gomez, Nicolas Keck
This week I worked extensively with Caitlyn and Enrique on performing user testing, and fine tuning our control scheme. I also re-soldered the Kontroller board a couple of times as weak joints broke during testing. Overall, I’ve strengthned many of the solder joints on our finger IMU which should allow for stringent use during our demo.
We have completed our MVP.
We are refining our project experience as much as possible, tuning according to user feedback.
This week I completed soldering of the Glove PCB. Specifically, I soldered the finger PCB to the connector coming from the Glove PCB. This now lets us perform tests with the completed glove controller. Below is an image of the fully-soldered IMU. We are still keeping the IMU on our breadboard for testing right now.
We are on track given our updated schedule from our interim demo. We are making good progress towards streamlining our controller and solidifying our control scheme.
Next week I will be working collaboratively with the rest of the team to make improvements to our control scheme and to close the loop between Kar and Kontroller.
A new manufacturing technique that I had to learn was how to solder SMT components to a PCB without a stencil, and where the component pins were on the bottom of the IC. This required me to watch a YouTube video on the topic, which demonstrated a technique of mixing flux and solder paste together on the board before using a hot air gun to solder. I successfully used this technique to solder our buck converter to the Kar PCB. Additionally, I had to learn more PCB rework skills for this project, due to the manufacturing issues with our PCBs. This was mostly self-taught, as I messed around with techniques of sticking wires and components to the boards until they worked properly.
End-to-end latency measurement
Control scheme viability
Entering the safety/reset state
This week I supported the interim demo by maintaining the Kar’s electronic systems and ensured that the Kar was properly setup for demo. This involved ensuring that the batteries were properly charged between demo sessions, and that the PCB was properly mounted to the Kar chassis. Additionally, after our demos I added an IMU to our Kar so that we can complete our haptic feedback loop between the Kar and the Kontroller.
We are on schedule for the most part. I was hoping to attach the finger IMU sensor to the Kontroller this week, but was not able to. However, the lack of progress on this goal was cancelled out by successfully adding the Kar IMU.
Next week I will be attaching the finger IMU sensor to the glove PCB so that we can begin the transition from our breadboard control system to our final control system.
This week I completed soldering of the Kar PCB, and the Glove PCB. I also integrated the Kar PCB with the Kar itself, and worked with the team to perform our first test where the Kar moved on the ground under its own power. There were a couple of integration issues to sort out, such as the electronic speed controller for our primary motor backdriving our power system on the Kar, but otherwise integration was a relatively smooth process. An image of the Kar PCB integrated with the Kar can be seen below:
Everything PCB-wise is going to schedule. We have a working Kar PCB prepared for our interim demo, and will be using the time we have from now until the final demo to refine our control systems and product in general.
Next week I will be working on supporting the interim demo, and keeping track of electrical faults as they come up. Additionally, I will need to attach the finger sensor to the glove PCB at some point in the week.
This week I practically completely finished assembly of the glove PCB. The only components which are missing are the haptic motor driver, which still needs to be acquired from Ideate; the LDO output capacitor, which ran out of stock on Digikey and will likely be acquired from Roboclub; and the LDO itself, as we identified a manufacturing issue that ensures we need to do extra work in order to attach the LDO to the PCB. A picture of the PCB soldering progress can be seen below. We also realized this week that due to an ordering error, we did not order all of the components needed for our Kar PCB, so these extra components have been ordered.
PCB assembly is going according to schedule. The Kar PCB missing components would have led to a setback if it had been noticed later, but it was noticed promptly at the beginning of last week which means we will be able to smoothly transition between assembly of the glove PCB and assembly of the Kar PCB.
I will finish the assembly of the glove PCB tomorrow (11/1), and assuming the Kar PCB components arrive on Monday I will begin and complete the Kar PCB assembly leading up to the interim demo.