embedded-systems

Firmware for microcontrollers involves writing code that runs directly on the hardware, managing peripherals, interrupts, and real-time constraints. You configure the MCU's registers, implement drivers for sensors and communication protocols, and handle timing-critical operations while optimizing for limited RAM and code space.

FreeRTOS is a real-time operating system that manages task scheduling and synchronization, letting you write predictable concurrent firmware. Bare-metal development writes directly to hardware without an OS, giving you full control but requiring manual interrupt and timing management. FreeRTOS suits complex multi-task systems; bare-metal suits simple, deterministic applications.

Protocol implementation requires writing HAL drivers that configure the MCU's peripheral registers, manage data transmission and reception, handle timing requirements, and integrate error detection. You initialize the peripheral, manage interrupts or polling for data transfer, and ensure proper synchronization between the MCU and connected devices.

Power optimization involves configuring low-power modes during idle periods, implementing wake-up strategies triggered by specific events, and minimizing clock speeds when full performance isn't needed. Proper sleep scheduling and peripheral clock gating significantly extend battery life on resource-constrained devices.

Embedded testing includes timing tests to verify deterministic execution, memory profiling to track RAM and code usage, and fault injection to validate error handling. These techniques confirm the firmware meets real-time deadlines, stays within resource constraints, and recovers gracefully from hardware faults.

Each platform uses platform-specific toolchains and SDKs for compilation and debugging, but core embedded principles—register configuration, interrupt handling, driver architecture—apply across vendors. Selecting an RTOS like FreeRTOS or a bare-metal approach depends on timing requirements and system complexity rather than the hardware choice.