Switching Microcontrollers Because of Shortages or Cost: Migrating Firmware Without a Rewrite
Part shortages and cost pressure force MCU changes mid-product. How I move firmware to new silicon without starting over.
The problem clients bring: "Our microcontroller has a long lead time, or a cheaper part would save us real money per unit. But our firmware is tied to the current chip."
What is really going wrong
- Application logic mixed directly with vendor driver calls everywhere.
- Timing that depends on one chip's clock and peripherals.
- Fear that a port means rewriting and retesting everything.
How I solve it
- Compare candidate parts against what the product really uses: memory, peripherals, power, supply.
- Separate application logic from hardware behind a thin board layer.
- Port the board layer to the new chip and keep the application unchanged.
- Run the same tests on old and new hardware to prove identical behaviour.
- Support both chips in one codebase while stock transitions.
What the client gets
Freedom to choose parts on price and availability, and firmware that is easier to move again next time.