OPL-Transmitter.ino

[kfjl]

/* ARDUINO One-Page LoRa TRANSMITTER 
 *  
 * AI Ra-01_V1.0 Semtech SX1278 ****** NOT BREADBOARD FRIENDLY !!!! ******
 *
 * Powered from computer usb or phone charger via FTDI module with jumper at 3.3V 
 *
 *  LoRa       Arduino
 *  3.3V        VCC       THREE POINT THREE VOLTS !!!.!!!       
 *  GND         GND
 *  SCK         SCK       (13)
 *  MISO        MISO      (12)
 *  MOSI        MOSI      (11)
 *  NSS         10
 *  RESET       9
 */

 #include <SPI.h>

 const int nss = 10;
 const int reset = 9;
 const int lora_int = 2;
 byte data = 0;
 byte tx_base = 0x80;
 byte regIrqFlags = 0;

void setup() {

  pinMode(reset,OUTPUT);
  pinMode(nss, OUTPUT);
  digitalWrite(nss,HIGH);
  digitalWrite(reset,HIGH);
  
  SPI.begin();
  Serial.begin(9600);

  // CONFIG TX 

  digitalWrite(reset,LOW);
  delayMicroseconds(100);                               // reset low 100 usec
  digitalWrite(reset,HIGH);
  delay(10);                                            // time to reset, mini 5 msec

  digitalWrite(nss,LOW);
  SPI.transfer(0x81);  SPI.transfer(0x00);              // Need to be in sleep mode to set LoRa mode
  digitalWrite(nss,HIGH);

  digitalWrite(nss,LOW);
  SPI.transfer(0x81);  SPI.transfer(0x88);              // LoRa, low freq mode
  digitalWrite(nss,HIGH);

  digitalWrite(nss,LOW);
  SPI.transfer(0x89);  SPI.transfer(0xF3);              // PA_BOOST
  digitalWrite(nss,HIGH);
 
  digitalWrite(nss,LOW);
  SPI.transfer(0x91);  SPI.transfer(0xF7);              // Set up for TXDone IRQ
  digitalWrite(nss,HIGH);
}

void loop() {                                           // TRANSMIT 1 byte payload
  
  digitalWrite(nss,LOW);
  SPI.transfer(0x81);  SPI.transfer(0x09);              // standby mode to set up packet
  digitalWrite(nss,HIGH);
  
  digitalWrite(nss,LOW);
  SPI.transfer(0x8D);  SPI.transfer(tx_base);           // set SPI pointer
  digitalWrite(nss,HIGH);

  digitalWrite(nss,LOW);
  SPI.transfer(0x80);  SPI.transfer(data);              // Write the byte to Fifo
  digitalWrite(nss,HIGH);

  digitalWrite(nss,LOW);
  SPI.transfer(0x81);  SPI.transfer(0x8B);              // TX on, low freq mode (send the byte)
  digitalWrite(nss,HIGH);

  delay(100);

  digitalWrite(nss,LOW);
  SPI.transfer(0x12);regIrqFlags =  SPI.transfer(0x00);     // Get flags reg
  digitalWrite(nss,HIGH);

  if(regIrqFlags) {                             // TXDone
    digitalWrite(nss,LOW);
    SPI.transfer(0x92); SPI.transfer(0xFF);     // Set flags reg to zero
    digitalWrite(nss,HIGH);
    Serial.print("Sent ");
    Serial.println(data); 
  }
    
  digitalWrite(nss,LOW);
  SPI.transfer(0x81);  SPI.transfer(0x88);             // TX and RX to sleep in LoRa mode (clear Fifo)
  digitalWrite(nss,HIGH);

  data=(data<10)?data+1:0;                // If data<10 then data=data+1 else data=0
  delay(900);
}