Firmware Modification for Embedded Device

I'm seeking an experienced Embedded Systems Engineer to modify existing device firmware on a functional device.

Key Tasks:
- Review existing firmware code
- Implement required feature enhancements
- Optimize and debug existing code
- Ensure compatibility with our hardware

Ideal Skills:
- Proven embedded systems development experience (AVR)
- Proficient in C for microcontroller programming
- Experience with I2C, UART, SPI protocols
- Familiar with hardware interfacing (sensors, displays, GSM modules, EEPROM)
- Ability to work with legacy codebases
- Knowledge of CodeVisionAVR

Deliverables:
- Modified source code with new features
- Clean documentation of changes
- Support during testing phase

This is a one-time project with potential for future collaboration.