Remote Pump Control Using 2x Heltec LoRa 32 Modules (ESP32 LoRa Boards)

Excerpt:
How I built a low-cost, long-range pump control system using just two Heltec LoRa 32 modules — no internet or GSM required.

Overview

Remote pumps — whether for boreholes, tanks, or irrigation — are often far from Wi-Fi, GSM, or cable runs. Here’s how I used two Heltec LoRa 32 (V2) boards to control and monitor a pump over a distance of more than 2 kilometers with zero cellular or internet coverage.

Why LoRa?

• Ultra-low power
• 2+ km line-of-sight range
• No SIM cards, no subscriptions
• Built-in OLED for diagnostics
• ESP32 onboard = full custom control

Hardware Used

Basic Setup

• Node 1 (Tank site):
• Reads input from a float switch or level sensor
• Sends LoRa message like {“start”:1} to Node 2
• Node 2 (Pump site):
• Listens for LoRa packets
• Activates or deactivates a relay based on the command
• Optional OLED feedback (status, signal strength)

Code Highlights (Arduino)

Sender:
“`cpp
LoRa.beginPacket();
LoRa.print(\”START\”);
LoRa.endPacket();

Reciever:

if (LoRa.parsePacket()) {
String cmd = LoRa.readString();
if (cmd == \”START\”) digitalWrite(relayPin, HIGH);
}

Real-World Results

• Tested with stock antennas: ~2.3 km range (line of sight)
• No packet loss in basic tests with float switches
• Installed in 2 plastic junction boxes with desiccant
• Power draw low enough to run off solar trickle charge

Tips for Builders

• Keep antennas vertical and away from metal
• Add watchdog timers to auto-restart if hung
• Use millis() instead of delay() for better timing
• Always debounce input buttons/switches

Final Thoughts

This setup has saved me from multiple pump overruns and dry tank headaches. It’s cheap, robust, and doesn’t depend on GSM or Wi-Fi — perfect for remote farms and off-grid water systems.

📩 Want the code or wiring diagram? Contact me and I’ll share it.