Embedded Environmental Communication System

I am building a compact embedded solution whose main role is to act as a communication system for live environmental monitoring. The unit must read temperature, humidity, air-quality indices, and soil-moisture levels, then push those readings reliably to a remote endpoint in real time.

Here is what I need from you:
• Hardware design: sensor selection, schematic, and PCB layout sized for low-power field deployment.
• Firmware: driver code for the temperature & humidity, air-quality, and soil-moisture sensors, along with a lightweight stack that formats the data and handles wireless transmission. I have no fixed protocol in mind, so you may propose BLE, LoRa, Wi-Fi, or another option that balances range and power.
• Data communication workflow: sample rate configuration, data packet structure, and a simple proof-of-concept dashboard or serial parser that shows the incoming readings clearly.
• Documentation: build files, BOM, flashing instructions, and a short user guide so I can reproduce the setup or hand it to manufacturing without guesswork.

Acceptance will be based on:
1. Accurate sensor readings demonstrated over at least a 24-hour test run.
2. Stable wireless link with no data loss at the agreed sample rate.
3. Clean, well-commented code that compiles without warnings.
4. A concise PDF showing schematic, board renders, and deployment steps.

If you have experience with low-power microcontrollers, RF module integration, and environmental sensor calibration, I would love to review your approach and timeline.