Firmware is never truly tested until you experience a real-time power brownout under heavy load.
⚡ The Problem: High-Current Spikes
When a dual-axis motor turret rapidly accelerates to lock onto a target setpoint, peak current draw can jump from 2 Amps to 35 Amps in 5 milliseconds.
If your power distribution board doesn’t have sufficient bulk capacitance or low-ESR decoupling:
- Battery voltage drops below the microcontroller’s 3.3V LDO regulator threshold.
- The MCU triggers a Brown-Out Reset (BOR).
- The turret instantly goes limp, reboots, and loses encoder zero position.
🛡️ The Architectural Solution
- Isolated Power Rails: Separate logic power (3.3V/5V) from high-current motor rails (12V/24V) via optocouplers and DC-DC buck regulators.
- Bulk Energy Storage: High-capacitance low-ESR reservoir banks right at the MOSFET gate driver terminals.
- Software Current Limits: Implementing acceleration ramp limits in firmware so torque requests don’t exceed battery discharge limits. ⚙️