Is there any "increase antenna gain" on arduino LMIC sketch?


(Kul2enai) #1

Hi,

I’m testing LoRa node range and RSSI with arduino UNO R3 and NiceRF LoRa V2.0 SX1276 915MHz.
I’ve tried to change many antenna such as

  • spring antenna 2.15 dBi gain
  • 6 cm antenna 2 dBi gain
  • 15 cm antenna 3 dBi gain
  • 26 cm antenna 3.5 dBi gain

and the result is make sense, the better and bigger antenna the better range and RSSI.
Now I want to increase its range and RSSI with coding.
So I want to know Is there any “increase antenna gain” on arduino sketch?

P.S. I’m using “ttn-abp” sketch from “ARDUINO IDM LMIC” framework library.
and here is my sketch

/*******************************************************************************
 * Copyright (c) 2015 Thomas Telkamp and Matthijs Kooijman
 *
 * Permission is hereby granted, free of charge, to anyone
 * obtaining a copy of this document and accompanying files,
 * to do whatever they want with them without any restriction,
 * including, but not limited to, copying, modification and redistribution.
 * NO WARRANTY OF ANY KIND IS PROVIDED.
 *
 * This example sends a valid LoRaWAN packet with payload "Hello,
 * world!", using frequency and encryption settings matching those of
 * the The Things Network.
 *
 * This uses ABP (Activation-by-personalisation), where a DevAddr and
 * Session keys are preconfigured (unlike OTAA, where a DevEUI and
 * application key is configured, while the DevAddr and session keys are
 * assigned/generated in the over-the-air-activation procedure).
 *
 * Note: LoRaWAN per sub-band duty-cycle limitation is enforced (1% in
 * g1, 0.1% in g2), but not the TTN fair usage policy (which is probably
 * violated by this sketch when left running for longer)!
 *
 * To use this sketch, first register your application and device with
 * the things network, to set or generate a DevAddr, NwkSKey and
 * AppSKey. Each device should have their own unique values for these
 * fields.
 *
 * Do not forget to define the radio type correctly in config.h.
 *
 *******************************************************************************/
#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>
#include <stdio.h>

//GPS
#include <SoftwareSerial.h>
#include <TinyGPS.h>
SoftwareSerial mySerial(8, 9);
// Module -> Arduino
//     TX -> Pin 8
//     RX -> Pin 9
TinyGPS gps;
void gpsdump(TinyGPS &gps);
void printFloat(double f, int digits = 2);
//GPS

// Count for interval losing
int count = 0;


// LoRaWAN NwkSKey, network session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
//c30464d6e404847c6b2bdcdfeee3e44a
static const PROGMEM u1_t NWKSKEY[16] = {  };

// LoRaWAN AppSKey, application session key
// This is the default Semtech key, which is used by the early prototype TTN
// network.
//6a997e1488064d3028579ea77942c623
static const u1_t PROGMEM APPSKEY[16] = {  };

// LoRaWAN end-device address (DevAddr)
//07ffa7f7
static const u4_t DEVADDR =  ;

// These callbacks are only used in over-the-air activation, so they are
// left empty here (we cannot leave them out completely unless
// DISABLE_JOIN is set in config.h, othe rwise the linker will complain).
void os_getArtEui (u1_t* buf) { }
void os_getDevEui (u1_t* buf) { }
void os_getDevKey (u1_t* buf) { }

// assign mydata size
static uint8_t mydata[48];
static osjob_t sendjob;

// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 1;

// Pin mapping
const lmic_pinmap lmic_pins = {
    .nss = 10,
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 5,
    .dio = {2, 3, LMIC_UNUSED_PIN},
};

void onEvent (ev_t ev) 
{
  
    Serial.print(os_getTime());
    Serial.print(": ");
    switch(ev) {
        case EV_SCAN_TIMEOUT:
            Serial.println(F("EV_SCAN_TIMEOUT"));
            break;
        case EV_BEACON_FOUND:
            Serial.println(F("EV_BEACON_FOUND"));
            break;
        case EV_BEACON_MISSED:
            Serial.println(F("EV_BEACON_MISSED"));
            break;
        case EV_BEACON_TRACKED:
            Serial.println(F("EV_BEACON_TRACKED"));
            break;
        case EV_JOINING:
            Serial.println(F("EV_JOINING"));
            break;
        case EV_JOINED:
            Serial.println(F("EV_JOINED"));
            break;
        case EV_RFU1:
            Serial.println(F("EV_RFU1"));
            break;
        case EV_JOIN_FAILED:
            Serial.println(F("EV_JOIN_FAILED"));
            break;
        case EV_REJOIN_FAILED:
            Serial.println(F("EV_REJOIN_FAILED"));
            break;
        case EV_TXCOMPLETE:
            Serial.println(F("EV_TXCOMPLETE (includes waiting for RX windows)"));
            if (LMIC.txrxFlags & TXRX_ACK)
              Serial.println(F("Received ack"));
            if (LMIC.dataLen) {
              Serial.println(F("Received "));
              Serial.println(LMIC.dataLen);
              Serial.println(F(" bytes of payload"));
            }
            // Schedule next transmission
            os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
            break;
        case EV_LOST_TSYNC:
            Serial.println(F("EV_LOST_TSYNC"));
            break;
        case EV_RESET:
            Serial.println(F("EV_RESET"));
            break;
        case EV_RXCOMPLETE:
            // data received in ping slot
            Serial.println(F("EV_RXCOMPLETE"));
            break;
        case EV_LINK_DEAD:
            Serial.println(F("EV_LINK_DEAD"));
            break;
        case EV_LINK_ALIVE:
            Serial.println(F("EV_LINK_ALIVE"));
            break;
         default:
            Serial.println(F("Unknown event"));
            break;
    }
}

void do_send(osjob_t* j)
{

    // Check if there is not a current TX/RX job running
    if (LMIC.opmode & OP_TXRXPEND) 
    {
        Serial.println(F("OP_TXRXPEND, not sending"));
    } 
    else 
    {

        // GPS
        bool newdata = false;
        unsigned long start = millis();
        
        while (millis() - start < 5000) 
        {
          if (mySerial.available()) 
          {
            char c = mySerial.read();
            if (gps.encode(c)) 
            {
              newdata = true;
              break;
            }
          }
        }
        
        // get Lat/Long
        char tmp_string[64] = "GPS:";
        if (newdata) 
        {
          long lat, lon;
          float flat, flon;
          unsigned long age, date, time, chars;
          unsigned short sentences, failed;
          char tmp_char1[15];
          char tmp_char2[15];
          
          gps.f_get_position(&flat, &flon, &age);
          //Convert float to char*
          dtostrf(flat, 6, 6, tmp_char1);
          dtostrf(flon, 6, 6, tmp_char2);
          strcat(tmp_string, tmp_char1);
          strcat(tmp_string, ",");
          strcat(tmp_string, tmp_char2);
        }
        else
        {
          Serial.println("Cannot receive any GPS data.");
        }
        // GPS


        // count
        count++;
        char tmp_char3[3];
        itoa (count,tmp_char3,10);
        strcat(tmp_string, "|Count:");
        strcat(tmp_string, tmp_char3);
        // count

      
        // print payload string
        Serial.println(tmp_string);   
             
        //Convert char* to uint8_t
        memcpy (mydata, tmp_string, strlen(tmp_string)+1 );
        
        // Prepare upstream data transmission at the next possible time.
        LMIC_setTxData2(1, mydata, sizeof(mydata)-1, 0);
        Serial.println(F("Packet queued"));
    }
    // Next TX is scheduled after TX_COMPLETE event.
}

void setup() 
{
    Serial.begin(9600);
    Serial.println(F("Starting"));

    #ifdef VCC_ENABLE
     For Pinoccio Scout boards

    pinMode(VCC_ENABLE, OUTPUT);
    digitalWrite(VCC_ENABLE, HIGH);
    delay(1000);
    #endif

    // GPS
    mySerial.begin(9600);
    
    // LMIC init
    os_init();
    // Reset the MAC state. Session and pending data transfers will be discarded.
    LMIC_reset();

    // Set static session parameters. Instead of dynamically establishing a session
    // by joining the network, precomputed session parameters are be provided.
    #ifdef PROGMEM
    // On AVR, these values are stored in flash and only copied to RAM
    // once. Copy them to a temporary buffer here, LMIC_setSession will
    // copy them into a buffer of its own again.
    uint8_t appskey[sizeof(APPSKEY)];
    uint8_t nwkskey[sizeof(NWKSKEY)];
    memcpy_P(appskey, APPSKEY, sizeof(APPSKEY));
    memcpy_P(nwkskey, NWKSKEY, sizeof(NWKSKEY));
    LMIC_setSession (0x1, DEVADDR, nwkskey, appskey);
    #else
    // If not running an AVR with PROGMEM, just use the arrays directly
    LMIC_setSession (0x1, DEVADDR, NWKSKEY, APPSKEY);
    #endif

    #if defined(CFG_eu868)
    // Set up the channels used by the Things Network, which corresponds
    // to the defaults of most gateways. Without this, only three base
    // channels from the LoRaWAN specification are used, which certainly
    // works, so it is good for debugging, but can overload those
    // frequencies, so be sure to configure the full frequency range of
    // your network here (unless your network autoconfigures them).
    // Setting up channels should happen after LMIC_setSession, as that
    // configures the minimal channel set.
    // NA-US channels 0-71 are configured automatically
    LMIC_setupChannel(0, 923200000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(1, 923400000, DR_RANGE_MAP(DR_SF12, DR_SF7B), BAND_CENTI);      // g-band
    LMIC_setupChannel(2, 923600000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(3, 923800000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(4, 924000000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(5, 924200000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(6, 924400000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(7, 924600000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(8, 924800000, DR_RANGE_MAP(DR_FSK,  DR_FSK),  BAND_MILLI);      // g2-band
    // TTN defines an additional channel at 869.525Mhz using SF9 for class B
    // devices' ping slots. LMIC does not have an easy way to define set this
    // frequency and support for class B is spotty and untested, so this
    // frequency is not configured here.
    #elif defined(CFG_us915)
    // NA-US channels 0-71 are configured automatically
    // but only one group of 8 should (a subband) should be active
    // TTN recommends the second sub band, 1 in a zero based count.
    // https://github.com/TheThingsNetwork/gateway-conf/blob/master/US-global_conf.json
    LMIC_selectSubBand(0);
    #endif

    // Disable link check validation
    LMIC_setLinkCheckMode(0);

    // TTN uses SF9 for its RX2 window.
    LMIC.dn2Dr = DR_SF9;

    // Set data rate and transmit power for uplink (note: txpow seems to be ignored by the library)
    LMIC_setDrTxpow(DR_SF7,14);

    // Start job
    do_send(&sendjob);
}

void loop() 
{
    os_runloop_once();
}

//GPS
void printFloat(double number, int digits)
{
  // Handle negative numbers
  if (number < 0.0) 
  {
     Serial.print('-');
     number = -number;
  }

  // Round correctly so that print(1.999, 2) prints as "2.00"
  double rounding = 0.5;
  for (uint8_t i=0; i<digits; ++i)
    rounding /= 10.0;
  
  number += rounding;

  // Extract the integer part of the number and print it
  unsigned long int_part = (unsigned long)number;
  double remainder = number - (double)int_part;
  Serial.print(int_part);

  // Print the decimal point, but only if there are digits beyond
  if (digits > 0)
    Serial.print("."); 

  // Extract digits from the remainder one at a time
  while (digits-- > 0) 
  {
    remainder *= 10.0;
    int toPrint = int(remainder);
    Serial.print(toPrint);
    remainder -= toPrint;
  }
}

(LoRaTracker) #2

What are the legal ERP limits in your part of the world ?