Development and refinement of PCB based on the existing layout

Need an electronics engineer to transfer an existing device from a breadboard to a full PCB project.

There is a working prototype assembled on a breadboard. It is necessary to analyze the current connections, correct the schematic if needed, develop a schematic diagram, and create a PCB layout for the subsequent production of a test batch.

The device is based on ESP32-S3 and includes:

• I2S microphone;
• RTC DS3231;
• LoRa SX1278;
• GPS module with UART and PPS;
• autonomous power supply;
• service connection for firmware and diagnostics;
• status indication.

What needs to be done:

• understand the existing prototype on the breadboard;
• check and refine the schematic diagram;
• select or clarify components, ratings, power supply, and protection;
• develop the PCB layout considering the features of ESP32-S3, I2S audio, LoRa, GPS, and RTC;
• provide connectors, test points, firmware, and diagnostics;
• perform ERC/DRC checks;
• prepare a set of files for production and assembly.

Expected results:

• output files in KiCad or Altium Designer;
• schematic diagram in PDF;
• PCB layout;
• Gerber and drill files;
• BOM;
• Pick&Place / CPL file;
• a brief description of the changes made, recommendations, and technical risks.

Preference will be given to a performer from Kyiv: it is desirable to have the opportunity to personally show the prototype, discuss details, and conduct a joint technical review if necessary. In the response, please indicate experience with ESP32, autonomous power supply, radio modules, and examples of similar work.