Cellular Temp-Humidity Sensor Design

I need a complete hardware-to-firmware solution for a low-power, standalone temperature and humidity monitor that relies on 4G/LTE rather than Wi-Fi. The core will be an ESP32 driving a SIM7600G module, paired with a DHT22 sensor. Collected readings must be published over MQTT to my Supabase/PostgreSQL back-end.

The device will sleep most of the time, wake on schedule, take a reading, push it securely, then drop back into deep sleep. It also has to recognise a lost cellular link, attempt reconnection gracefully, and log any failures for later review. Power comes from a Li-po pack, topped up through a USB-C port, so the design needs an efficient charging and protection stage.

Please deliver:
• Complete, readable schematic (PDF + source)
• Production-ready PCB layout with Gerber files
• Fully documented Arduino/C++ firmware including:
– Deep-sleep logic with wake intervals adjustable over serial
– MQTT routine targeting Supabase/PostgreSQL
– Robust reconnection and error handling for the SIM7600G
– Battery management and basic health reporting

Acceptance tests will be a successful 24-hour bench run on battery, uninterrupted MQTT posting every 15 minutes, and current draw below 200 µA in sleep. If you have suggestions for component choices or layout tweaks that improve efficiency or reliability, feel free to highlight them.