A race car built in 19 hours using dual RC airsoft motors and custom-designed motor controllers, mounted on a repurposed satellite receiver frame. As one of four finalists out of 15 teams, we achieved the fastest lap time at 17 seconds. My role focused on robust MOSFET stage design and safe signal-handling firmware to ensure high current reliability and controlled motor behavior.
Built from an old satellite receiver's frame, our team designed the vehicle to have steering mechanism with dual rear RC airsoft motors driven by custom designed motor controllers within the 19 hour time constraint.
🚗🔋 Our project was ranked as the top qualifier among the 4 finalist teams selected from a total of 15. We achieved a record of 17 seconds lap time compared to the average 25 seconds.
💡 From the challenges, Here's what I learned from as a hardware design member of the team:
1) Designing robust MOSFET Output Stages - The airsoft motors were strong in torque with the cost of heavy current draw, which initially led to the overheating of off-the-shelf motor controllers. This experience taught me the importance of proper MOSFET selection and use of drivers, especially to decrease charge time for PWM control. I addressed the issue by designing a custom output stage using MOSFETS connected in parallel to double current capacity, paired with a gate driver along with cooling fans for thermal management
2) Configuring proper startup logic - The RC receiver and motor signal converter initially showed some undefined state on bootup including sudden motor acceleration. I discovered that during pairing mode and transmitter disconnect, the RC receiver will send pulse signals pulse signals outside the expected operating domain. To resolve this, I designed a robust firmware for the Arduino based motor signal converter to detect invalid pulse signals while ensuring MOSFET driver's were only enabled within safe signal domains.
If you would like to learn more about our Race Car design, please check out our full project on Github:
