I am a Master student and in my project I have to collect data from different types of sensors and send it to the cloud, I have done this with the DH11 sensor using existing examples and it worked well, but when I wanted to change the sensor and send the Ultrasonic HC-SR04 data to the cloud via the LoRa gateway it doesn't work , the data collected by the sensor is detected by the Arduino board and sent to the gateway, but I can't use it or even read it. Here is the code I used
LoRa Gateway:
#include <SPI.h>
#include <RH_RF95.h>
#include <Console.h>
#include <Process.h>
RH_RF95 rf95;
#define BAUDRATE 115200
float frequency = 868.0;
void setup() {
Bridge.begin(BAUDRATE);
Console.begin();
if (!rf95.init())
Console.println("init failed");
// Setup ISM frequency
rf95.setFrequency(frequency);
// Setup Power,dBm
rf95.setTxPower(13);
rf95.setSyncWord(0x34);
}
void loop() {
if (rf95.waitAvailableTimeout(2000)) {
String K="";
uint8_t buf[RH_RF95_MAX_MESSAGE_LEN];//receive data buffer
uint8_t len = sizeof(buf);//data buffer length
if (rf95.recv(buf, &len))//Check if there is incoming data
{
//recdata( buf, len);
Console.print("Get LoRa Packet: ");
for (int i = 0; i < len; i++)
{
Console.print(buf[i],HEX);
K=K+(buf[i],HEX);
Console.print(" ");
}
Console.println();
for (int i = 0; i < len; i++)
{
X = X+buf[i];
}
Console.println(X);
Console.println("K :");
Console.println(K);
K="";
for (int i = 0; i < len; i++)
{
String((char *)buf[i]);
}
Console.println(K);
}
}
}
Arduino board :
/*HC-SR04_TEST :
Use SR04 ultro sonic sensor to measure distance and show it on the serial monity
Hardware Connection:
Trig < -- > Arduino D3
Echo pin < -- > Arduino D4
VCC < -- > Arduino 5v
GND < -- > Arduino GND
by Dragino <[email protected]>
Dragino Technology Co., Limited
*/
#include <SPI.h>
#include <RH_RF95.h>
RH_RF95 rf95;
byte bGlobalErr;
char sr04_dat[3];
// Set up SR04 pins to Arduino
const int TrigPin = 3;
const int EchoPin = 4;
float duration, distance, frequency = 868.0;
unsigned int count = 1;
void setup()
{ // initial serial connection
Serial.begin(9600);
pinMode(TrigPin, OUTPUT);
// Set up pin to input mode to detect wave width.
pinMode(EchoPin, INPUT);
if (!rf95.init())
Serial.println("init failed");
// Setup ISM frequency
rf95.setFrequency(frequency);
// Setup Power,dBm
rf95.setTxPower(13);
rf95.setSyncWord(0x34);
Serial.println("Ultrasonic sensor:");
}
void ReadSR04()
{
bGlobalErr=0;
byte sr04_in;
byte i;
//pinMode(dht_dpin,OUTPUT);
//digitalWrite(dht_dpin,LOW);//Pull Low A0 and send signal
//delay(30);//Delay > 18ms so DHT11 can get the start signal
digitalWrite(TrigPin, LOW);
delayMicroseconds(2);
digitalWrite(TrigPin, HIGH);
delayMicroseconds(10);
digitalWrite(TrigPin, LOW);
//digitalWrite(dht_dpin,HIGH);
//delayMicroseconds(40);//Check the high level time to see if the data is 0 or 1
//pinMode(dht_dpin,INPUT);
// delayMicroseconds(40);
//dht_in=digitalRead(dht_dpin);//Get A0 Status
// Serial.println(dht_in,DEC);
//if(dht_in){
// bGlobalErr=1;
// return;
//}
//delayMicroseconds(80);//DHT11 send response, pull low A0 80us
//dht_in=digitalRead(dht_dpin);
duration = pulseIn(EchoPin, HIGH);
distance = duration*0.034/2;
//if(!dht_in){
// bGlobalErr=2;
// return;
//}
delayMicroseconds(80);//DHT11 send response, pull low A0 80us
};
void loop()
{
Serial.print("########### ");
Serial.print("COUNT=");
Serial.print(count);
Serial.println(" ###########");
count++;
ReadSR04();
Serial.print("Distance : ");
Serial.print(distance);
Serial.print("cm");
Serial.println();
String mystring;
byte leng;
int i;
mystring = String(distance);
leng = sizeof(mystring);
char data[sizeof(mystring)];
for(i = 0;i < (sizeof(mystring)); i++)
{
data[i] = mystring[i];
}
rf95.send(data, leng);//Send LoRa Data
uint8_t buf[RH_RF95_MAX_MESSAGE_LEN];//Reply data array
uint8_t len = sizeof(buf);//reply data length
if (rf95.waitAvailableTimeout(3000))// Check If there is reply in 3 seconds.
{
// Should be a reply message for us now
if (rf95.recv(buf, &len))//check if reply message is correct
{
pinMode(13, OUTPUT);
digitalWrite(13, HIGH);
Serial.print("Got Reply from Gateway: ");//print reply
Serial.println((char*)buf);
delay(400);
digitalWrite(13, LOW);
//Serial.print("RSSI: "); // print RSSI
//Serial.println(rf95.lastRssi(), DEC);
}
else
{
Serial.println("recv failed");//
rf95.send(data, strlen((char*)data));//resend if no reply
}
}
else
{
Serial.println("No reply, is LoRa gateway running?");//No signal reply
rf95.send(data, strlen((char*)data));//resend data
}
delay(3000);
Serial.println("");
}
This picture contains the screeshot of the serial monitor of the sensor + Arduino board (COM5) and the serial monitor of the LoRa gateway (dragino board)
