Summary
My first project on my university’s Formula SAE Electric design team was designing multiple PCBs for the dashboard assembly for the 2022/23 season vehicle. This system integrated many features that were helpful for visual diagnostics, driver control, and driver feedback, alongside competition rules required functionalities.
Dashboard PCB Multi-board Assembly View in Altium Designer
2022/23 Vehicle “Thruna”
Mainboard
The dashboard mainboard PCB acted as a central controller for the dashboard assembly. Using an STM32F4 microntroller, several indication RGB LEDs were included to indicate faults and warnings associated with systems around the vehicle using the CAN bus. Interfaces were also designed to connect the two other dashboard elements to the mainboard microcontroller.
Dashboard Mainboard 3D Render
7-Segment Display Board
In order to display more complicated numerical data to the driver, I designed a 7-segment display board that was driven by the mainboard through a board-to-board connector. To reduce the pin usage on the microcontroller, daisy-chained shift registers were implemented to enable full control of all 72 segments on the board using only a serial data, clock, and refresh pin. The data that was chosen to display to the driver was battery temperature (°C), vehicle speed (km/hr), and battery state of charge (%).
Dashboard 7-Segment Display Board 3D Render
Driver Input Board
The driver input board was mounted on the opposite side of the cockpit to the mainboard. It included two mechanical switches to switch into Drive Active and another to enable torque vectoring. A rotary dial was also added to enable switching between up-to 16 different drive modes. Compared to the prior generation driver input board, I designed a priority encoder circuit to increase bussing efficiency to the mainboard by encoding the rotary encoder position over 4 bits instead of 16 bits. This enabled use of a smaller ribbon cable and connectors on both the driver input and mainboards.
Driver Input Board 3D Render
Priority Encoder Circuit Schematic