I am facing an issue “Cannot init” messaage in Serial Monitor when I tried to connect DHT11 sensor with Arduino UNO + GSM 800 C module and Blynk app. I changed the baud rate to 19200 and still same error. Can you please help?
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I have posted the code below
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I created the template in Blynk.Cloud and copied the auth code to the program.
//-----------------------------------------------------------------------
/* Comment this out to disable prints and save space */
#define BLYNK_PRINT Serial
//-----------------------------------------------------------------------
/* Fill-in your Template ID (only if using Blynk.Cloud) */
#define BLYNK_TEMPLATE_ID "TMPLE-OB8GVE"
#define BLYNK_DEVICE_NAME "GSM Blynk"
#define BLYNK_AUTH_TOKEN "5lRz70tm-E9VVE68I5D9yphxm_4lsomQ"
//-----------------------------------------------------------------------
// Select your modem:
#define TINY_GSM_MODEM_SIM800
//#define TINY_GSM_MODEM_SIM900
//#define TINY_GSM_MODEM_M590
//#define TINY_GSM_MODEM_A6
//#define TINY_GSM_MODEM_A7
//#define TINY_GSM_MODEM_BG96
//#define TINY_GSM_MODEM_XBEE
//-----------------------------------------------------------------------
// Default heartbeat interval for GSM is 60
// If you want override this value, uncomment and set this option:
//#define BLYNK_HEARTBEAT 30
//-----------------------------------------------------------------------
#include <TinyGsmClient.h>
#include <BlynkSimpleTinyGSM.h>
//-----------------------------------------------------------------------
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = BLYNK_AUTH_TOKEN;
//-----------------------------------------------------------------------
// Your GPRS credentials
// Leave empty, if missing user or pass
char apn[] = "internet";
char user[] = "";
char pass[] = "";
//-----------------------------------------------------------------------
// Hardware Serial on Mega, Leonardo, Micro
//#define SerialAT Serial1
//-----------------------------------------------------------------------
// or Software Serial on Uno, Nano
#include <SoftwareSerial.h>
SoftwareSerial SerialAT(2, 3); // RX, TX
TinyGsm modem(SerialAT);
//-----------------------------------------------------------------------
#include <DHT.h>
#define DHT11_PIN 4
#define DHTTYPE DHT11
DHT dht(DHT11_PIN, DHTTYPE);
//-----------------------------------------------------------------------
BlynkTimer timer;
#define INTERVAL 1000L
//-----------------------------------------------------------------------
/************************************************************************************
* This function sends Arduino's up time every second to Virtual Pin.
* In the app, Widget's reading frequency should be set to PUSH. This means
* that you define how often to send data to Blynk App.
**********************************************************************************/
void SendDhtData()
{
//-----------------------------------------------------------------------
//Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
float h = dht.readHumidity();
//-----------------------------------------------------------------------
//Read temperature as Celsius (the default)
float t = dht.readTemperature();
//-----------------------------------------------------------------------
// Check if any reads failed and exit early (to try again).
if (isnan(h) || isnan(t)) {
Serial.println(F("Failed to read from DHT sensor!"));
return;
}
//-----------------------------------------------------------------------
//Compute heat index in Celsius (isFahreheit = false)
float hic = dht.computeHeatIndex(t, h, false);
//-----------------------------------------------------------------------
Serial.print("Temperature: ");
Serial.println(t);
Serial.print("Humidity: ");
Serial.println(h);
Serial.println("------------------------------------------");
//-----------------------------------------------------------------------
// You can send any value at any time.
// Please don't send more that 10 values per second.
Blynk.virtualWrite(V0, t);
Blynk.virtualWrite(V1, h);
//-----------------------------------------------------------------------
}
/************************************************************************************
* setup() function
**********************************************************************************/
void setup()
{
//-----------------------------------------------------------
// Debug console
Serial.begin(115200);
delay(10);
//-----------------------------------------------------------
// Set GSM module baud rate
SerialAT.begin(115200);
//SerialAT.begin(9600,SWSERIAL_8N1,D3,D4);
delay(3000);
//-----------------------------------------------------------
dht.begin();
//-----------------------------------------------------------
// Restart takes quite some time
// To skip it, call init() instead of restart()
Serial.println("Initializing modem...");
modem.restart();
// Unlock your SIM card with a PIN
//modem.simUnlock("1234");
//-----------------------------------------------------------
Blynk.begin(auth, modem, apn, user, pass);
//-----------------------------------------------------------
// Setup a function to be called every second
timer.setInterval(INTERVAL, SendDhtData);
//-----------------------------------------------------------
}
/************************************************************************************
* loop() function
**********************************************************************************/
void loop()
{
Blynk.run();
timer.run();
}
