LoRa Weather Station with Long-Range Telemetry

Weather monitoring in farms, campuses and industrial yards fails at the connectivity step: WiFi does not reach the field, and GSM data plans cost money every month for a few bytes of sensor data. LoRa exists precisely for this gap — a chirp spread-spectrum radio that trades bitrate for kilometres of range on milliwatts of power, in licence-free spectrum. This project builds the classic LoRa weather pair: a remote node with an ESP32, an RFM95 LoRa module and a DHT22 temperature-humidity sensor (plus a pressure sensor), and a base-station node with its own LoRa receiver and an LCD showing live readings. The demo places the sensor node across the lab or campus and streams packets to the receiver, showing live temperature, humidity, packet count and signal strength. Students learn the full wireless-sensor-network pipeline — sensing, packet framing with node IDs and checksums, link-budget thinking and the deep-sleep discipline that lets a node live on batteries.

1. The sensor node wakes from deep sleep, powers the DHT22 and pressure sensor, and takes stabilized readings.
2. The ESP32 packs the readings with its node ID, an incrementing sequence number and a checksum into a compact LoRa packet.
3. The RFM95 transmits the packet on 865 MHz using chirp spread-spectrum modulation at the configured spreading factor.
4. The receiver node's RFM95 picks up the packet; the firmware verifies the checksum and discards any corrupted frames.
5. Valid readings are shown on the receiver's LCD with temperature, humidity, pressure, RSSI and sequence number.
6. The sensor node returns to deep sleep until the next cycle, and the receiver logs the stream over serial for analysis.

Tech stack:

• ESP32 DevKit (sensor node and receiver node)
• RFM95 LoRa module (SX1276, 865 MHz ISM)
• DHT22 temperature-humidity sensor
• Barometric pressure sensor (BMP280)
• 16x2 LCD on receiver node
• Battery pack for sensor node
• Arduino IDE (C/C++ firmware, RadioLib/LoRa library)
• Serial monitor for packet logging

• [Long-range LoRa link] RFM95 (SX1276) modules on 865 MHz — India's licence-free ISM band — carry sensor packets point-to-point with a design target of up to ~2 km in open line-of-sight conditions.
• [Temperature, humidity and pressure sensing] The node reads a DHT22 (±0.5 °C, ±2% RH per datasheet) and a barometric pressure sensor, transmitting all three in each packet.
• [Structured packets with checksum] Every transmission carries a node ID, sequence number, sensor payload and checksum, so the receiver rejects corrupted packets instead of displaying garbage.
• [Receiver display station] The base node shows live temperature, humidity, pressure, last-packet RSSI and packet sequence on an LCD — the link health is visible at a glance.
• [Deep-sleep power design] The sensor node spends most of its life in ESP32 deep sleep, waking every few minutes to sense and transmit — the standard technique for battery-powered field nodes.
• [Configurable radio parameters] Spreading factor, bandwidth and transmit power are adjustable in firmware, letting the student demonstrate the range-vs-airtime tradeoff in the viva.
• [Battery operation] The sensor node runs from a battery pack, so the demo genuinely shows untethered field operation rather than a bench-bound prototype.

• Two working LoRa nodes: battery-powered sensor node + LCD receiver station (ESP32, RFM95 modules, DHT22, BMP280, antennas)
• Complete firmware for both nodes (packet framing, checksum, deep sleep, receiver display)
• Radio configuration guide (frequency, spreading factor, bandwidth, power settings for India)
• Field-test procedure (range walk-test with RSSI logging template)
• Circuit and wiring documentation
• Project report PDF (LoRa modulation background, link budget, packet design, power analysis)
• PPT presentation for final review
• Viva Q&A preparation document (spread spectrum, ISM bands, deep sleep, checksums)
• Setup and demonstration guide

• The ~2 km figure is a design target for open line-of-sight; buildings, trees and terrain reduce real range significantly — the field-test procedure exists precisely to measure this honestly.
• LoRa is low-bitrate by design (tens of bytes per packet, minutes between transmissions); it cannot carry video, audio or web traffic.
• Operation is on the 865–867 MHz ISM band with duty-cycle discipline; the firmware defaults respect this, and continuous transmission is not permitted.
• The receiver shows data on its LCD and serial log only — there is no cloud dashboard or phone app in this build; that is a separate project.
• Weatherproofing the field node (enclosure, sensor radiation shield) is documented as a buyer-done step; the kit ships as an electronics prototype.