Debug GSM Module Integration

I need an experienced embedded systems or electronics freelancer to debug a communication failure between a custom GSM module and an Atmega-based microcontroller using I2C.

Key Tasks:
- Analyze provided GSM PCB design and schematics.
- Understand interfacing between the main device and GSM module.
- Debug to identify root cause of failure.
- Suggest or implement modifications for stable integration.

Ideal Skills:
- Embedded Systems
- GSM Modules (SIM800C)
- PCB Design & Debugging
- I2C Communication
- Microcontroller Integration

Deliverables:
- Root cause analysis
- Fix or modification suggestion
- Optional: code update if necessary