Example Code for Arduino-Uploading Temperature and Humidity Data to LoRaWAN Gateway

Hardware Preparation

• DFR0994 Romeo ESP32-S3 x 1
• LoRaWAN Indoor Gateway (868MHz Version) or LoRaWAN Indoor Gateway (915MHz Version) x1
• SEN0330 FermionSHT30 temperature and humidity sensor x1 (or other SHT temperature and humidity sensor using the same SHT3x code base)

Software Preparation

• Download Arduino IDE: Click to download Arduino IDE
• Add ESP32 board to Arduino IDE
• Please install the DFRobot_LoRaWAN_ESP32S3 library before use.
• Please install the DFRobot_SHT3X library
• About how to install the library?

Note:

• LoRaWAN protocol stack version: 1.0.3
• You need to set the data parsing format to "text" on the gateway.

Sample Code

#include "DFRobot_LoRaWAN.h"
#include <DFRobot_SHT3x.h>

// Button pin
#define BTN_PIN 18  // GPIO2, 3, 11, 12, 13 can all trigger external wake-up

LCD_OnBoard screen;

#define BG_COLOR        COLOR_RGB565_BLACK      // Screen background color
#define TEXT_COLOR      COLOR_RGB565_GREEN      // Screen font color

#define TEXT_FONT       &FreeMono9pt7b          // font
#define TEXT_SIZE       1                       // Screen font size
#define LINE_HEIGHT     18                      // Line height
#define POX_X           0                       // Screen print position X coordinate
#define POX_Y           15                      // Screen print position Y coordinate
#define LINE_1          0                       // Line number
#define LINE_2          1
#define LINE_3          2
#define LINE_4          3

// Data packet transmission interval
#define APP_INTERVAL_MS 30000
const uint8_t DevEUI[8] = {0xDF, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11};
const uint8_t AppEUI[8] = {0xDF, 0xB7, 0xB7, 0xB7, 0xB7, 0x00, 0x00, 0x00};
const uint8_t AppKey[16] = {
  0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 
  0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10};

uint8_t buffer[255];
uint8_t port = 2;
LoRaWAN_Node node(DevEUI, AppEUI, AppKey, CLASS_A);

DFRobot_SHT3x sht3x;

// Rejoin count
RTC_DATA_ATTR uint8_t CurReJoinTimes = 0;

// Join network callback function
void joinCb(bool isOk, int16_t rssi, int8_t snr)
{
    screen.fillScreen(BG_COLOR);    
    screen.setTextColor(TEXT_COLOR);
    screen.setFont(TEXT_FONT);
    screen.setTextSize(TEXT_SIZE);

    if(isOk){
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
        screen.printf("JOIN SUCCESS");
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_2);
        screen.printf("Accept Packet");
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_3);
        screen.printf("Rssi = %d", rssi);
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_4);
        screen.printf("Snr = %d", snr);
        delay(1000);
        node.deepSleepMs(APP_INTERVAL_MS);  // Deep sleep after successful network join        
    }else{
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
        screen.printf("OTAA join Err!");
        delay(2000);
        // Backoff join procedure
        CurReJoinTimes++; 
        uint64_t backoff_time_ms = 5000 * (1ULL << (CurReJoinTimes - 1));
        backoff_time_ms = (backoff_time_ms > 300000) ? 300000 : backoff_time_ms;
        node.deepSleepMs(backoff_time_ms);
    }  
}

void userSendConfirmedPacket(void)
{    
    float temperature = sht3x.getTemperatureC();
    float humidity = sht3x.getHumidityRH();
    screen.fillScreen(BG_COLOR);    
    screen.setTextColor(TEXT_COLOR);
    screen.setFont(TEXT_FONT);
    screen.setTextSize(TEXT_SIZE);
    screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
    screen.printf("Temp: %.2f C", temperature);
    screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_2);
    screen.printf("Humi: %.2f %%", humidity);
    char data[64];
    snprintf((char*)data, sizeof(data), "T:%.2f,H:%.2f", temperature, humidity);
    uint32_t datalen = strlen(data);
    memcpy(buffer, data, datalen);
    node.sendUnconfirmedPacket(port, buffer, datalen);
    delay(4000);  //A minimum delay of 4 seconds is required
    node.deepSleepMs(APP_INTERVAL_MS);
}

void setup()
{
    Serial.begin(115200);

    screen.begin(); 
    screen.fillScreen(BG_COLOR);    
    screen.setTextColor(TEXT_COLOR);
    screen.setFont(TEXT_FONT);
    screen.setTextSize(TEXT_SIZE);
    while (sht3x.begin() != 0) {
        screen.fillScreen(BG_COLOR);  
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
        screen.printf("SHT3x Err");
        delay(1000);
    }
    delay(1000);

    // Set to wake up using a button press
    esp_sleep_enable_ext0_wakeup((gpio_num_t )BTN_PIN, LOW);
    esp_sleep_wakeup_cause_t wakeup_reason = esp_sleep_get_wakeup_cause();
    if(!(node.init(/*dataRate=*/DR_4, /*txEirp=*/16))){     // Initialize the LoRaWAN node, set the data rate and Tx Eirp
        screen.fillScreen(BG_COLOR);        
        screen.setTextColor(TEXT_COLOR);
        screen.setFont(TEXT_FONT);
        screen.setTextSize(TEXT_SIZE);
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
        screen.printf("LoRaWAN Init Failed!");
        while(1);
    }

    if(!node.isJoined()) {
        screen.fillScreen(BG_COLOR);        
        screen.setTextColor(TEXT_COLOR);
        screen.setFont(TEXT_FONT);
        screen.setTextSize(TEXT_SIZE);
        screen.setCursor(POX_X, POX_Y + LINE_HEIGHT * LINE_1);
        screen.printf("Join Request");
        node.join(joinCb);                                  // Join the LoRaWAN network 
    } else {
        userSendConfirmedPacket();                          // Send data
    }    
}

void loop()
{
    delay(1000);
}