Telephony Schematic & Firmware Development

I have a working draft of a telephony-grade hardware design and I need a seasoned electrical engineer to finish it up.

I will supply the current PDFs/PCB files, and a brief block-level write-up. The files contain only basic documentation.

Once we agree the hardware is sound, I’ll have a shortlist of component-level questions (why a particular codec, timing tolerance on the crystal, etc.). Clear, practical answers here will decide the final BOM.

The next stage is firmware which will bring it to life. I need clean, well-documented code—preferably in C or C++—that compiles under GCC or a comparable open-source toolchain.

Deliverables
• Answer one question about component substitution
• (Later on, next project, after I have a prototype produced) complete firmware source, makefile/project files, and a verified binary ready to flash

Any tool is fine as long as you can export to industry-standard formats. I look forward to tightening up the hardware and bringing the code to life with you!