# Remote Sensor Deployment Guide

A practical guide for deploying LoRa mesh sensor nodes in the field for environmental monitoring, agriculture, and infrastructure monitoring.

## Example use cases from the community

### Weather station network

Multiple BME280-equipped nodes reporting temperature, humidity, and pressure at regular intervals. A gateway node (with internet uplink) receives all reports and logs them to a database. The mesh provides coverage even when nodes are miles apart across a farm or forest.

### Soil moisture monitoring

Capacitive soil moisture sensors (e.g. STEMMA Soil Sensor) connected to a RAK4631 WisBlock. Node wakes every 30 minutes (this interval is user-configurable), reads moisture level, transmits if below threshold (irrigation alert), returns to sleep. With a typical pack (e.g. a 3000 mAh cell at well under 1 mA average) the battery can last many months on a single charge with occasional solar topping.

### Water level monitoring

Ultrasonic or pressure transducer water level sensors for creek gauging, tank monitoring, or flood early warning. The mesh allows data to reach a gateway even when the sensor is in a remote canyon without cellular coverage. Note: a hobbyist mesh is a supplementary indicator only - official NWS/USGS warnings remain the authoritative flood-warning source.

### Gate and door alerts

Reed switch or Hall effect sensor triggers a mesh message when a gate, shed door, or access point is opened. Uses a latching trigger architecture (interrupt-driven, not polling) for maximum battery life.

## Choosing hardware for IoT sensor nodes

<table id="bkmrk-boardmcusleep-curren"><thead><tr><th>Board</th><th>MCU</th><th>Sleep current</th><th>Sensor interfaces</th><th>Best for</th></tr></thead><tbody><tr><td>Heltec T096</td><td>nRF52840</td><td>~13 µA (per Heltec spec, bare board)</td><td>I²C, SPI, UART, ADC</td><td>Ultra-low power remote sensors</td></tr><tr><td>RAK4631 WisBlock</td><td>nRF52840</td><td>~2 µA (MCU only)</td><td>WisBlock sensor slot ecosystem</td><td>Modular sensor builds with WisBlock sensors</td></tr><tr><td>Heltec V4</td><td>ESP32-S3</td><td>~10 µA (bare-MCU deep-sleep figure; verify against Heltec V4 spec - typical whole-board deep-sleep current is higher)</td><td>I²C, SPI, UART, ADC, WiFi</td><td>Gateway nodes that also serve WiFi</td></tr><tr><td>XIAO nRF52840</td><td>nRF52840</td><td>~5 µA (see Seeed XIAO nRF52840 power spec)</td><td>I²C, SPI, UART</td><td>Compact DIY sensor builds</td></tr></tbody></table>

## The RAK WisBlock sensor ecosystem

RAKwireless produces a modular ecosystem (WisBlock) where sensor modules snap directly onto the RAK4631 base board without soldering (see each module's RAKwireless datasheet page):

- RAK1901: Temperature + humidity (SHTC3)
- RAK1902: Barometric pressure (LPS22HB)
- RAK1904: 3-axis accelerometer (LIS3DH) - vibration / motion detection
- RAK12010: Ambient light sensor (see RAK12010 datasheet)
- RAK12019: UV index sensor (see RAK12019 datasheet)
- RAK12500: GPS module (u-blox ZOE-M8Q)
- RAK13010: SDI-12 interface for agricultural soil/water sensors (see RAK13010 datasheet)

This ecosystem significantly reduces build complexity - no custom PCB or wiring required for common sensor types.

## Deployment checklist

- Enclosure rated IP65+ with UV-resistant housing
- Cable glands on all penetrations (sensor cable, antenna, power)
- Desiccant pack inside enclosure; replace annually
- Solar panel and MPPT charge controller for remote sites
- **In-line fuse (or PTC/polyfuse) on the battery positive lead**, sized just above peak load, to protect against a short-circuit fire if outdoor wiring chafes, floods, or is damaged. A lithium pack can source tens of amps into a fault.
- LiFePO4 battery (not LiPo) for outdoor/temperature-variable deployments - but note that LiFePO4, like all lithium chemistries, must **not be charged below 0 °C (32 °F)**; cold-charging causes lithium plating and is hazardous. Use a charge controller with a low-temperature charge cutoff. (LiFePO4 tolerates cold *discharge* better than LiPo, which is why it is preferred outdoors.)
- Antenna mounted outside enclosure (even 1 meter above the enclosure adds range)
- GPS coordinates recorded and logged - for the network map and maintenance records
- Label the enclosure with node name and maintainer contact

## Getting data off the mesh

Sensor data on the mesh is useful only if someone can read it. Options for data collection:

1. **Manual retrieval:** A person with a phone and the app periodically reads nodes. Simple but not real-time.
2. **Room server (MeshCore):** A MeshCore Room Server (running on dedicated nRF52840 or ESP32 hardware) is a store-and-forward BBS for room chat history, not an MQTT/telemetry gateway. Verify the Room Server's role against the MeshCore Room Server documentation; MQTT bridging is a separate gateway component, not a built-in Room Server feature.
3. **Python API script:** For MeshCore, the meshcore-py library is scoped to message/contact logging - use a script on a server-connected node to log incoming messages/contacts to a database (see the [MeshCore Python API](https://wiki.meshamerica.com/books/meshcore/page/meshcore-python-api) page). For logging actual structured *sensor telemetry*, use the Meshtastic Telemetry + MQTT path instead.
4. **Internet-bridged gateway:** A MeshCore node with WiFi (Heltec V4) connected to a home network; the Python library reads data and forwards to any cloud service.