ESP32-C3 + OLED + MPU6050 Battery Powered Board – Fix Power & Charging Circuit + Complete Firmware

Project Overview We have designed a custom PCB that integrates the following components: MCU: ESP32-C3 SuperMini OLED: LCD1306 (Chinese module) MEMS: MPU6050 board Battery: 3.7V / 300mAh Li-ion battery PCB: Custom PCB to mount the above 3 modules Current Status: A previous developer designed and manufactured the PCB. Test firmware was written and successfully communicated with both the OLED and MPU6050. When a USB-C cable is plugged in, the board powers on and works correctly. When the USB-C cable is unplugged, the board does NOT run on battery power (it shuts down immediately). A battery charging circuit exists on the board, but it has not been verified whether charging actually works. Problems to Be Solved: 1. Battery Discharge Circuit Issue The battery discharge path has a design flaw. You must review the schematic and PCB layout, then modify/fix the discharge circuit. 2. Battery Charging Circuit Make the charging circuit work correctly. Select a reasonable charging current to prevent the board from overheating during charging and discharging. 3. Complete Firmware (not just driver-level test code) Write integrated firmware that properly drives both the OLED and MPU6050. The existing firmware is only for basic board testing (driver level only). 4. Sleep & Wake-up Logic with Verified Power Consumption Implement reasonable sleep and wake-up functionality in the firmware. You must estimate the sleep current during the design phase, and I will approve that target. After the physical prototype is built, the measured sleep current must match the estimated value. Working Method (Important) This project will be delivered as a complete working prototype from your side. You will: Review and modify the existing EasyEDA schematic and PCB layout. Order/prototype the modified PCB (or modify an existing board). Verify that: Battery discharge works properly. Battery charging works properly with safe current. The board runs correctly on battery power. Write the complete firmware (OLED + MPU6050 + sleep/wake). Measure and confirm sleep current matches your estimate. Send me all final deliverables (see below). I will not manufacture or test anything myself until you deliver a proven design. Deliverables After you confirm everything works on your prototype, you must provide: Complete EasyEDA project (schematic, PCB layout, Gerber files, BOM) Final firmware for ESP32-C3 SuperMini (well-commented, ready to download) A short report including: Estimated vs. measured sleep current Charging current value and thermal observation Any design notes or warnings for manufacturing Important: After I receive your files, I must be able to manufacture the PCB, download the firmware, and immediately get a fully working board without any further debugging. Required Skills: EasyEDA (or similar PCB design) ESP32-C3 / ESP-IDF or Arduino Battery management (Li-ion charging/discharging circuits) Low-power design and measurement OLED (I2C) and MPU6050 (I2C) driver development Sleep/wake logic for battery-powered devices Due to the nature of this work, I prefer a freelancer based in mainland China. Developers who already have the current version of the board on hand are also welcome to apply.