Step1-LORA_GPS_Setup

Hardware used 

1. heltec_wifi_lora_32_V2 board has oled ( 2 - Sender & Receiver )  37.52Euro

2. BN-220 GPS Module $11.11

3. SUNWALK 6V 4.2W Solar Panel Charger Monocrystalline Solar Cell Phone Charger for DIY Charger Power Bank with USB Output : -7.47Euro

4. ESP32 ESP32S For Wemos For Raspberry Pi 18650 Battery Charge Shield  $1.46

Lora Sender :  Download Link

Lora Reciever : Download Link

This project uses two Heltec WiFi LoRa 32 V2 boards to transmit GPS coordinates over LoRa radio. A BN-220 GPS module is connected to the sender board, which reads coordinates and transmits them to a receiver board via LoRa at 868MHz.

• ESP32 RECEIVES on GPIO 17 (U2_RXD) — this is the important data line

• GPIO 2 is used as TX to GPS (not strictly needed, but keeps Serial2 happy)

• Serial config: SERIAL_8N1 (8 data bits, No parity, 1 stop bit) — BN-220 default

• DO NOT use GPIO 13 for GPS with LoRa active — SPI.begin() claims this pin internally

Libraries used 

1. Lora ( by Sandeeo Mistry )

• Purpose: Drives the SX1276 LoRa radio chip

• Install: Arduino Library Manager → search "LoRa"

• Why this library: Works without any license key (unlike the official Heltec LoRaWan_APP library which requires Mcu.begin() + license). Provides simple blocking API: LoRa.beginPacket(), LoRa.print(), LoRa.endPacket()

• GitHub: https://github.com/sandeepmistry/arduino-LoRa

2. TinyGPS++ (by Mikal Hart)

• Purpose: Parses NMEA sentences from the GPS module into usable lat/lng/alt/speed/time values

• Install: Arduino Library Manager → search "TinyGPSPlus"

• How it works: You feed raw bytes from Serial2 into gps.encode(byte), and it parses the NMEA protocol automatically. Query gps.location.lat(), gps.satellites.value(), etc.

• GitHub: https://github.com/mikalhart/TinyGPSPlus

3. ESP8266 and ESP32 OLED Driver for SSD1306 (by ThingPulse)

• Purpose: Drives the on-board 0.96" OLED display

• Install: Arduino Library Manager → search "SSD1306Wire" or "ESP8266 and ESP32 OLED"

• Why this library: Works standalone without the Heltec library. Provides display.drawString(), display.clear(), display.display()

• GitHub: https://github.com/ThingPulse/esp8266-oled-ssd1306

4. SPI (built-in)

• Purpose: SPI bus communication for the LoRa radio

• Install: Included with ESP32 Arduino core — no separate install needed

• Usage: SPI.begin(SCK, MISO, MOSI, CS) configures the bus for LoRa

Arduino IDE Setup 

Board Manager URL : 

https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/releases/download/0.0.9/package_heltec_esp32_index.json

Board Selection:

• Tools → Board → Heltec ESP32 Arduino → WiFi LoRa 32(V2)

• Or use ESP32 Dev Module (works fine with Sandeep Mistry library)

Upload Settings:

• Upload Speed: 921600

• Serial Monitor Baud: 115200

Data Format (LoRa Packet)

With GPS fix:

54.940362,-7.743982,45.0,12,#58

│          │         │    │   └── packet count

│          │         │    └────── satellites

│          │         └─────────── altitude (meters)

│          └───────────────────── longitude

└──────────────────────────────── latitude

Without GPS fix:

NF,ST:0,CH:7182,#13

│   │    │       └── packet count

│   │    └────────── chars received from GPS

│   └─────────────── satellites visible

└─────────────────── No Fix