Save downlink data for ESP32 lorawan

#1

Ive been searching all day and on every other post ive found on here there was no actual explanation for how to save the downlink data from the ESP32_LoRaWAN master library into a global variable so that it may be used elsewhere in the program. Ive seen people try to answer this question by pasting the OTAA_LED example with no follow on explanation to how it works. I see that you can make case statements in the void app((uint8_t data); function, but the problem is that you cant call the app() function in other parts of the sketch. Any solutions?

this is the example im referring to.

/*
  • HelTec Automation™ LoRaWAN 1.0.2 OTAA example use OTAA, CLASS A
  • Function summary:
    • You can use port 4 to control the LED light.
    • If the issued value is 1(ASCII), the lamp will be lit.
    • The release value is 2(ASCII) and the light will be turned off.
    • use internal RTC(150KHz);
    • Include stop mode and deep sleep mode;
    • 15S data send cycle;
    • Informations output via serial(115200);
    • Only ESP32 + LoRa series boards can use this library, need a license
  • to make the code run(check you license here: http://www.heltec.cn/search/);
  • You can change some definition in “Commissioning.h” and “LoRaMac-definitions.h”
  • HelTec AutoMation, Chengdu, China.
  • 成都惠利特自动化科技有限公司
  • https://heltec.org
  • support@heltec.cn

*this project also release in GitHub:
*https://github.com/HelTecAutomation/ESP32_LoRaWAN
*/

#include <ESP32_LoRaWAN.h>
#include “Arduino.h”

/*license for Heltec ESP32 LoRaWan, quary your ChipID relevant license: http://resource.heltec.cn/search */
uint32_t license[4] = {0x4915A653,0xC69E42EE,0x0D9EA6D4,0xB5201468};

/* OTAA para*/
uint8_t DevEui[] = { 0x22, 0x32, 0x33, 0x00, 0x00, 0x88, 0x88, 0x02 };
uint8_t AppEui[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
uint8_t AppKey[] = { 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x66, 0x01 };

/* ABP para*/
uint8_t NwkSKey[] = { 0x15, 0xb1, 0xd0, 0xef, 0xa4, 0x63, 0xdf, 0xbe, 0x3d, 0x11, 0x18, 0x1e, 0x1e, 0xc7, 0xda,0x85 };
uint8_t AppSKey[] = { 0xd7, 0x2c, 0x78, 0x75, 0x8c, 0xdc, 0xca, 0xbf, 0x55, 0xee, 0x4a, 0x77, 0x8d, 0x16, 0xef,0x67 };
uint32_t DevAddr = ( uint32_t )0x007e6ae1;

/LoraWan channelsmask, default channels 0-7/
uint16_t userChannelsMask[6]={ 0x00FF,0x0000,0x0000,0x0000,0x0000,0x0000 };

/LoraWan Class, Class A and Class C are supported/
DeviceClass_t loraWanClass = CLASS_C;

/the application data transmission duty cycle. value in [ms]./
uint32_t appTxDutyCycle = 15000;

/OTAA or ABP/
bool overTheAirActivation = true;

/ADR enable/
bool loraWanAdr = true;

/* Indicates if the node is sending confirmed or unconfirmed messages */
bool isTxConfirmed = true;

/* Application port */
uint8_t appPort = 2;

/*!

  • Number of trials to transmit the frame, if the LoRaMAC layer did not
  • receive an acknowledgment. The MAC performs a datarate adaptation,
  • according to the LoRaWAN Specification V1.0.2, chapter 18.4, according
  • to the following table:
  • Transmission nb | Data Rate
  • ----------------|-----------
  • 1 (first) | DR
  • 2 | DR
  • 3 | max(DR-1,0)
  • 4 | max(DR-1,0)
  • 5 | max(DR-2,0)
  • 6 | max(DR-2,0)
  • 7 | max(DR-3,0)
  • 8 | max(DR-3,0)
  • Note, that if NbTrials is set to 1 or 2, the MAC will not decrease
  • the datarate, in case the LoRaMAC layer did not receive an acknowledgment
    */
    uint8_t confirmedNbTrials = 8;

/*LoraWan debug level, select in arduino IDE tools.

  • None : print basic info.
  • Freq : print Tx and Rx freq, DR info.
  • Freq && DIO : print Tx and Rx freq, DR, DIO0 interrupt and DIO1 interrupt info.
  • Freq && DIO && PW: print Tx and Rx freq, DR, DIO0 interrupt, DIO1 interrupt and MCU deepsleep info.
    */
    uint8_t debugLevel = LoRaWAN_DEBUG_LEVEL;

/LoraWan region, select in arduino IDE tools/
LoRaMacRegion_t loraWanRegion = ACTIVE_REGION;

#define LEDPin 25 //LED light
void app(uint8_t data)
{
// lora_printf(“data:%d\r\n”,data);
switch(data)
{
case 49:
{
pinMode(LEDPin,OUTPUT);
digitalWrite(LEDPin, HIGH);
break;
}
case 50:
{
pinMode(LEDPin,OUTPUT);
digitalWrite(LEDPin, LOW);
break;
}
case 51:
{
break;
}
default:
{
break;
}
}
}

void downLinkDataHandle(McpsIndication_t *mcpsIndication)
{
lora_printf("+REV DATA:%s,RXSIZE %d,PORT %d\r\n",mcpsIndication->RxSlot?“RXWIN2”:“RXWIN1”,mcpsIndication->BufferSize,mcpsIndication->Port);
lora_printf("+REV DATA:");
app(mcpsIndication->Buffer[0]);

for(uint8_t i=0;iBufferSize;i++)
{
lora_printf("%02X",mcpsIndication->Buffer[i]);
}
lora_printf("\r\n");
}

static void prepareTxFrame( uint8_t port )
{
appDataSize = 4;//AppDataSize max value is 64
appData[0] = 0x00;
appData[1] = 0x01;
appData[2] = 0x02;
appData[3] = 0x03;
}

// Add your initialization code here
void setup()
{
Serial.begin(115200);
while (!Serial);
SPI.begin(SCK,MISO,MOSI,SS);
Mcu.init(SS,RST_LoRa,DIO0,DIO1,license);
deviceState = DEVICE_STATE_INIT;
}

// The loop function is called in an endless loop
void loop()
{
switch( deviceState )
{
case DEVICE_STATE_INIT:
{
#if(LORAWAN_DEVEUI_AUTO)
LoRaWAN.generateDeveuiByChipID();
#endif
LoRaWAN.init(loraWanClass,loraWanRegion);
break;
}
case DEVICE_STATE_JOIN:
{
LoRaWAN.join();
break;
}
case DEVICE_STATE_SEND:
{
prepareTxFrame( appPort );
LoRaWAN.send(loraWanClass);
deviceState = DEVICE_STATE_CYCLE;
break;
}
case DEVICE_STATE_CYCLE:
{
// Schedule next packet transmission
txDutyCycleTime = appTxDutyCycle + randr( -APP_TX_DUTYCYCLE_RND, APP_TX_DUTYCYCLE_RND );
LoRaWAN.cycle(txDutyCycleTime);
deviceState = DEVICE_STATE_SLEEP;
break;
}
case DEVICE_STATE_SLEEP:
{
LoRaWAN.sleep(loraWanClass,debugLevel);
break;
}
default:
{
deviceState = DEVICE_STATE_INIT;
break;
}
}
}

#2

You can refer to this example for rewriting.