A CAN bus is a robust communication system that lets multiple UAV components such as flight controllers, sensors, and power modules communicate over a single shared two-wire network. It reduces complex wiring by allowing devices to be daisy-chained instead of individually connected.

It is used in UAV systems because it is lightweight, highly reliable in electrically noisy environments, and supports real-time data exchange, making it ideal for mission-critical drone applications.

I²C, SPI, and UART sensors cannot be connected straight onto a CAN bus, because CAN is a different communication protocol. Instead, these sensors need a bridge or interface node (such as a CAN-enabled microcontroller or module) that reads the sensor data via I²C/SPI/UART and then transmits it onto the CAN network.

In UAV systems, this is a common approach because it lets you integrate almost any sensor into a DroneCAN or Cyphal ecosystem, keeping wiring simple while maintaining a scalable, unified CAN architecture.

To daisy-chain JST-GH CAN devices correctly, you connect each device in a linear chain using the CAN_H, CAN_L, power, and ground lines, rather than wiring everything back to a central hub.

Each device connects “in and out” so the bus runs from the flight controller → device → next device, keeping the wiring short, clean, and low-weight. It’s important to maintain correct polarity (CAN_H to CAN_H, CAN_L to CAN_L), ensure solid ground continuity, and place proper termination resistors at only the two physical ends of the CAN bus.