ESP32-LoRa Heltec

ESP32 (32 bits, 2 cores, 180 MHz)

• Connectivity
  • WiFi
  • BLE
  • LoRa (SX1276) 433MHz, 868MHz, 915MHz

Links

• ESP32 WiFi LoRa
• Diagram Pinout
• Github

Installation

• On MacOS

mkdir -p ~/Documents/Arduino/hardware
cd ~/Documents/Arduino/hardware
git clone https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series.git heltec
cd heltec/esp32
git submodule update --init --recursive
cd tools
python get.py

Configuration

ESP32 LoRa Config

Programs

Board 1 (Sender)

Open and load the schetch : Examples > LoRaLibrary > OLED_LoRa_Sender

Board 2 (Receiver)

Open and load the schetch : Examples > LoRaLibrary > OLED_LoRa_Receiver

Add LoRaWAN configuration

Add the following statements into the 2 schetches.

...

// LoRa API https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/blob/master/esp32/libraries/LoRa/API.md

// LoRaWAN Parameters
#define BAND    868100000  //you can set band here directly,e.g. 868E6,915E6
#define PABOOST false
#define TXPOWER 14
#define SPREADING_FACTOR 12
#define BANDWIDTH 125000
#define CODING_RATE 5
#define PREAMBLE_LENGTH 8
#define SYNC_WORD 0x34

void configForLoRaWAN()
{
  LoRa.setTxPower(TXPOWER);
  LoRa.setSpreadingFactor(SPREADING_FACTOR);
  LoRa.setSignalBandwidth(BANDWIDTH);
  LoRa.setCodingRate4(CODING_RATE);
  LoRa.setPreambleLength(PREAMBLE_LENGTH);
  LoRa.setSyncWord(SYNC_WORD);
  LoRa.crc();
}

String loraCfg = "Cfg:";
void  displayLoRaConfig(int x, int y){
  loraCfg = 
            "fr " + String(BAND/1000000, DEC)
          + " sf" + String(SPREADING_FACTOR, DEC)
          + " bw" + String(BANDWIDTH/1000, DEC)
          + " cr" + String(CODING_RATE, DEC) + "/4";
  display.drawString(x, y, loraCfg);
  loraCfg =        
          + " pr" + String(PREAMBLE_LENGTH, DEC)
          + " pw" + String(TXPOWER, DEC)
          + " sw" + String(SYNC_WORD, HEX)
          ;
  display.drawString(x, y+10, loraCfg);
}

...

  // should be done before LoRa.begin
  configForLoRaWAN();
  
  if (!LoRa.begin(BAND,PABOOST)) {
    display.drawString(0, 0, "Starting LoRa failed!");
    display.display();
    while (1);
  }
  displayLoRaConfig(0,20);
  display.drawString(0, 0, "LoRa Initial success!");

...

  display.display();
...

Simple LoRaWAN Sender (in ABP mode / No ADR)

Under construction

Install LMIC

• https://github.com/berkutta/esp32_lmic
• https://github.com/espressif/esp-idf
• https://github.com/matthijskooijman/arduino-lmic

Misc

• https://github.com/unprovable/LoRaChat
• https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic/10247/18