Firmware

Firmware is a special type of software that is permanently stored in a device’s memory and is responsible for its basic operation. It controls how the device works at the lowest level – meaning how hardware communicates with software and which core functions the device performs. Firmware is typically stored in ROM, EEPROM, or Flash memory. Firmware is therefore a crucial link between hardware and software that defines how a device operates. Without firmware, hardware would be just a non-functional collection of components, and software would have nothing to run on.

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What does firmware do?

Initializes hardware when the device is powered on.
Controls basic functions of the device (e.g. inputs, outputs, sensors).
Ensures communication between hardware and higher software layers.
Contains the device’s operational logic.

Difference between hardware, software, and firmware:

Term	What it is	Example
Hardware	Physical components of a device	Processor, memory, display, motor, sensors
Software	Programs and applications running on top of firmware	Windows, Android, mobile applications
Firmware	Low-level control program stored in the device	BIOS/UEFI, router firmware, ETU unit firmware

Main differences in simple terms:

Hardware = the body of the device.
Firmware = the brain of the device.
Software = the applications the device uses.

Can firmware be updated?

Yes. Most modern devices allow firmware updates, which can:

Fix bugs.
Improve stability.
Add new features.
Increase security.

Firmware in airsoft:

ETU / MOSFET units: Control rate of fire, firing modes, active braking, battery protection, and more.
Chronographs: Firmware evaluates BB velocity and energy.
Electronic sights: Control brightness, modes, and automatic power-off.