Key Engineering Takeaways
- •CAN bus uses differential pair lines (CAN_H, CAN_L) terminated with 120Ω resistors at each bus extremity to cancel common-mode noise.
- •Message priority is determined by identifier bits—lower ID numbers automatically win bus arbitration without packet collision or retries.
- •Modern robotic arms (Unitree, Robstride, MyActuator) communicate via 1Mbps CAN packets sending target torque, angle, and velocity.
Prerequisites
- • Differential signaling
- • Microcontroller C++
Differential Bus Physical Layer & Non-Destructive Bit Arbitration
CAN bus was engineered for harsh automotive environments. Its dominant (0) and recessive (1) bit states allow deterministic priority arbitration. If two joint actuators transmit at the exact same microsecond, the higher-priority emergency stop frame wins without corrupting data.
Tags:#CAN Bus#CAN-FD#Industrial#Robotic Arm#Firmware#Actuators