Arduino code to send voltage and current value to chirpstack and recieve downlink to turn on and off LED

Hello all,
I humbly write to get help, i am in dare need of help here.
My project i am building a system I want my device to send voltage and current value to the server.
I have installed the server on my gateway,
I first configured to send Hello world. this was well recieved at the server
but when i modify the code to send my voltage and current sensor values, although data arrives at the server, they do not make any sense. so please i need help to send my sensor data up and at the same time be able to receive downlink. my code is as shown below

 * Copyright (c) 2015 Thomas Telkamp and Matthijs Kooijman
 * Copyright (c) 2018 Terry Moore, MCCI
 * 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.
 * 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
 * arduino-lmic/project_config/lmic_project_config.h or from your BOARDS.txt.

 // References:
 // [feather] adafruit-feather-m0-radio-with-lora-module.pdf

#include <lmic.h>
#include <hal/hal.h>
#include <SPI.h>

const float vpp = 0.004882813;//(5.0/ 1024.0)
float sensitivity = 0.100; // 0.066 for 30A, 0.185 for X05B, 0.100 for 20A
const int analogInput = A0; 

// For normal use, we require that you edit the sketch to replace FILLMEIN
// with values assigned by the TTN console. However, for regression tests,
// we want to be able to compile these scripts. The regression tests define
// COMPILE_REGRESSION_TEST, and in that case we define FILLMEIN to a non-
// working but innocuous value.
# define FILLMEIN 0
# warning "You must replace the values marked FILLMEIN with real values from the TTN control panel!"
# define FILLMEIN (#dont edit this, edit the lines that use FILLMEIN)

// LoRaWAN NwkSKey, network session key
// This should be in big-endian (aka msb).
static const PROGMEM u1_t NWKSKEY[16] = {0x32, 0xF8, 0xD5, 0x7D, 0x2A, 0x08, 0xE2, 0x4F, 0xED, 0x83, 0x14, 0x90, 0x0F, 0x1A, 0xE2, 0x62};

// LoRaWAN AppSKey, application session key
// This should also be in big-endian (aka msb).
static const u1_t PROGMEM APPSKEY[16] = { 0xAB, 0x0A, 0xEE, 0xD3, 0xE9, 0xBB, 0x62, 0xE5, 0x3F, 0x95, 0xEE, 0x7C, 0x98, 0xEF, 0x57, 0xCD };

// LoRaWAN end-device address (DevAddr)
// See
// The library converts the address to network byte order as needed, so this should be in big-endian (aka msb) too.
static const u4_t DEVADDR = 0x00BC3BBE ; // <-- Change this address for every node!

// 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 arduino-lmic/project_config/lmic_project_config.h,
// otherwise the linker will complain).
void os_getArtEui (u1_t* buf) { }
void os_getDevEui (u1_t* buf) { }
void os_getDevKey (u1_t* buf) { }

 //byte payload[4]
static uint8_t payload[5];
static osjob_t sendjob;

// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 30;

// Pin mapping
// Adapted for Feather M0 per p.10 of [feather]
const lmic_pinmap lmic_pins = {
    .nss = 10,                       // chip select on feather (rf95module) CS
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 9,                       // reset pin
    .dio = {2, 6, 7}, // assumes external jumpers [feather_lora_jumper]
                                    // DIO1 is on JP1-1: is io1 - we connect to GPO6
                                    // DIO1 is on JP5-3: is D2 - we connect to GPO5

void onEvent (ev_t ev) {
    Serial.print(": ");
    switch(ev) {
        case EV_SCAN_TIMEOUT:
        case EV_BEACON_FOUND:
        case EV_BEACON_MISSED:
        case EV_BEACON_TRACKED:
        case EV_JOINING:
        case EV_JOINED:
        || This event is defined but not used in the code. No
        || point in wasting codespace on it.
        || case EV_RFU1:
        ||     Serial.println(F("EV_RFU1"));
        ||     break;
        case EV_JOIN_FAILED:
        case EV_REJOIN_FAILED:
        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(F(" bytes of payload"));
            // Schedule next transmission
            os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
        case EV_LOST_TSYNC:
        case EV_RESET:
        case EV_RXCOMPLETE:
            // data received in ping slot
        case EV_LINK_DEAD:
        case EV_LINK_ALIVE:
        || This event is defined but not used in the code. No
        || point in wasting codespace on it.
        || case EV_SCAN_FOUND:
        ||    Serial.println(F("EV_SCAN_FOUND"));
        ||    break;
        case EV_TXSTART:
        case EV_TXCANCELED:
        case EV_RXSTART:
            /* do not print anything -- it wrecks timing */
        case EV_JOIN_TXCOMPLETE:
            Serial.println(F("EV_JOIN_TXCOMPLETE: no JoinAccept"));
            Serial.print(F("Unknown event: "));
            Serial.println((unsigned) ev);

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 {
// read current value from  current sensor
     float Current= 0;
      //for(int i = 0; i < 1000; i++) {
      float value1= analogRead(analogInput);
      int counts = value1 ;
     float svoltage = counts * vpp;
      svoltage -=2.50;
      Current = svoltage/sensitivity;
      //Serial.print ("PV-CURRENT:");
      Serial.print   ( Current ); 
     // Serial.print  ("A");
// read voltage from voltage divider
const float R1 = 10000.0; //  
     const float R2 = 4700.0; // 
     float value = analogRead(A2);
     float vout = value * vpp; // 0.004882813;//(5.0/ 1024.0)see text
     float Voltage = vout / (R2/(R1+R2)); 
    //Serial.print ("PV-Voltage:");
   // Serial.print("V");
   /* uint32_t payloadCurrent = Current*100;
        // int -> bytes
        byte CurrentLow = lowByte(payloadCurrent);
        byte CurrentHigh = highByte(payloadCurrent);
        // place the bytes into the payload
        payload[0] = CurrentLow;
        payload[1] = CurrentHigh;

        // float -> int
        uint32_t payloadVoltage = Voltage*100;
        // int -> bytes
        byte VoltageLow = lowByte(payloadVoltage);
        byte VoltageHigh = highByte(payloadVoltage);
        payload[2] = VoltageLow;
        payload[3] = VoltageHigh;
        // Prepare upstream data transmission at the next possible time.
         //sprintf(outstrFinal,"%s,%s", outstr,outstr1);
               //tx(outstrFinal, txdone_func);
        LMIC_setTxData2(1, payload, sizeof(payload)-1, 0);
       Serial.println(F("Packet queued"));
    // Next TX is scheduled after TX_COMPLETE event.

void setup() {
//    pinMode(13, OUTPUT);
    while (!Serial); // wait for Serial to be initialized
    delay(100);     // per sample code on RF_95 test

    #ifdef VCC_ENABLE
    // For Pinoccio Scout boards
    pinMode(VCC_ENABLE, OUTPUT);
    digitalWrite(VCC_ENABLE, HIGH);

    // LMIC init
    // Reset the MAC state. Session and pending data transfers will be discarded.

    // 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 (0x13, DEVADDR, nwkskey, appskey);
    // If not running an AVR with PROGMEM, just use the arrays directly
   // LMIC_setSession (0x13, DEVADDR, NWKSKEY, APPSKEY);

   /* #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. The LMIC doesn't let you change
    // the three basic settings, but we show them here.

    // We'll disable all 72 channels used by TTN
    for (int c = 0; c < 9; c++){
    //  LMIC_disableChannel(c);

    // We'll only enable Channel 16 (905.5Mhz) since we're transmitting on a single-channel
   /*LMIC_setupChannel(0, 868100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(1, 868300000, DR_RANGE_MAP(DR_SF12, DR_SF7B), BAND_CENTI);      // g-band
   LMIC_setupChannel(2, 868500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(3, 867100000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(4, 867300000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(5, 867500000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(6, 867700000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(7, 867900000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);      // g-band
    LMIC_setupChannel(8, 868800000, 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) || defined(CFG_au915)
    // NA-US and AU 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.
    #elif defined(CFG_as923)
    // Set up the channels used in your country. Only two are defined by default,
    // and they cannot be changed.  Use BAND_CENTI to indicate 1% duty cycle.
    // LMIC_setupChannel(0, 923200000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);
    // LMIC_setupChannel(1, 923400000, DR_RANGE_MAP(DR_SF12, DR_SF7),  BAND_CENTI);


// Disable link check validation

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

    // Set data rate and transmit power for uplink

    // Start job
void loop() {

Thanks for sharing your code.
Could you please explain the pinout ? I am using a NodeMCU ESP12E

const lmic_pinmap lmic_pins = {
    .nss = 10,                       // chip select on feather (rf95module) CS
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 9,                       // reset pin
    .dio = {2, 6, 7}, // assumes external jumpers [feather_lora_jumper]
                                    // DIO1 is on JP1-1: is io1 - we connect to GPO6
                                    // DIO1 is on JP5-3: is D2 - we connect to GPO5

I don't really understand what it stands for.

Many thanks,