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This blog haven’t update for a loooog looooooong time, last article is published at mid October last year.

Revisit here, partly because LikeCoin starts a campaign for Mining beta 2, which distributes 30,000 LIKE every day. Mining Beta 1 requires medium, despite I join the subscriptions recently (profile: @hang321), last few weeks I was occupied with something else.

Now thanks to LikeCoin team provides a nice WordPress widget, just few clicks and simple plugin installation, now every blog post appended with a like coin button.

Let’s see how campaign goes, and I needa think about what type of topics to post. As I am slow in typing Chinese, most likely I will post something IT related blog in mixed with Cantonese and English.

Info if anyone interested:

I have brought a arduino kit in 2016 but haven’t played with it. Finally have some taste on it.

Install sketch – official software from arduino

Add “Adafruit unified sensor” & SimpleDHT library in sketch, then create a new file.

Code

/* install "Adafruit unified sensor" and simpleDHT library in sketch */
#include <Adafruit_Sensor.h>
#include <DHT.h>

/* Include the software serial port library */
#include <SoftwareSerial.h>
/* to communicate with the Bluetooth module's TXD pin */
#define BT_SERIAL_TX 10
/* to communicate with the Bluetooth module's RXD pin */
#define BT_SERIAL_RX 11
/* Initialise the software serial port */
SoftwareSerial BluetoothSerial(BT_SERIAL_TX, BT_SERIAL_RX);

/*  what digital pin DHT connected to */
#define DHTPIN 7
// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("Temperature and Humidity to bluetooth");
  dht.begin();

  BluetoothSerial.begin(9600);
  delay(1000);
  
  // Should respond with OK
  BluetoothSerial.print("AT");
  waitForResponse();
  
  // Should respond with its version
  BluetoothSerial.print("AT+VERSION");
  waitForResponse();
  
  // Set pin to 1234
  BluetoothSerial.print("AT+PIN1234");
  waitForResponse();
  
  // Set the name to BLU
  BluetoothSerial.print("AT+NAMEBLU");
  waitForResponse();

  Serial.println("Finished setup!");
}

void loop() {
  // Give it time to calibrate
  delay(10000);
  
  float h = dht.readHumidity();
  // Read Celsius
  float t = dht.readTemperature();
  // Read Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);

  // Check errors
  if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Compute heat index in Fahrenheit (the default)
  // float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  // float hic = dht.computeHeatIndex(t, h, false);

  Serial.println("Humidity: " + String(h) + "%, Temperature: " + String(t) + "^C");
  BluetoothSerial.println("Humidity: " + String(h) + "%, Temperature: " + String(t) + "^C");
}

// Function to pass BlueTooth output through to serial port output
void waitForResponse() {
  delay(1000);
  while (BluetoothSerial.available()) {
    Serial.write(BluetoothSerial.read());
  }
  Serial.write("\n");
}

/* install "Adafruit unified sensor" and simpleDHT library in sketch */

#include <Adafruit_Sensor.h>

#include <DHT.h>

/* Include the software serial port library */

#include <SoftwareSerial.h>

/* to communicate with the Bluetooth module's TXD pin */

#define BT_SERIAL_TX 10

/* to communicate with the Bluetooth module's RXD pin */

#define BT_SERIAL_RX 11

/* Initialise the software serial port */

SoftwareSerial BluetoothSerial(BT_SERIAL_TX, BT_SERIAL_RX);

/* what digital pin DHT connected to */

#define DHTPIN 7

// Uncomment whatever type you're using!

#define DHTTYPE DHT11 // DHT 11

//#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321

//#define DHTTYPE DHT21 // DHT 21 (AM2301)

DHT dht(DHTPIN, DHTTYPE);

void setup() {

Serial.begin(9600);

Serial.println("Temperature and Humidity to bluetooth");

dht.begin();

BluetoothSerial.begin(9600);

delay(1000);

// Should respond with OK

BluetoothSerial.print("AT");

waitForResponse();

// Should respond with its version

BluetoothSerial.print("AT+VERSION");

waitForResponse();

// Set pin to 1234

BluetoothSerial.print("AT+PIN1234");

waitForResponse();

// Set the name to BLU

BluetoothSerial.print("AT+NAMEBLU");

waitForResponse();

Serial.println("Finished setup!");

}

void loop() {

// Give it time to calibrate

delay(10000);

float h = dht.readHumidity();

// Read Celsius

float t = dht.readTemperature();

// Read Fahrenheit (isFahrenheit = true)

float f = dht.readTemperature(true);

// Check errors

if (isnan(h) || isnan(t) || isnan(f)) {

Serial.println("Failed to read from DHT sensor!");

return;

}

// Compute heat index in Fahrenheit (the default)

// float hif = dht.computeHeatIndex(f, h);

// Compute heat index in Celsius (isFahreheit = false)

// float hic = dht.computeHeatIndex(t, h, false);

Serial.println("Humidity: " + String(h) + "%, Temperature: " + String(t) + "^C");

BluetoothSerial.println("Humidity: " + String(h) + "%, Temperature: " + String(t) + "^C");

}

// Function to pass BlueTooth output through to serial port output

void waitForResponse() {

delay(1000);

while (BluetoothSerial.available()) {

Serial.write(BluetoothSerial.read());

}

Serial.write("\n");

}

Verify code, then connect the Ardunio board, and upload the file.

If it failed to upload, disconnect the bluetooth module. sending/receiving bluetooth data may interrupt the code upload.

Now let’s see the value from receiver via bluetooth, the simplest way to connect a android phone. Pair it up by bluetooth, install a terminal app, e.g. Bluetooth Terminal HC-05. (blueTerm does not work for my old GS3)

value will display on screen:

Connections:

reference:

Arduino Bluetooth Wireless Communication

http://www.instructables.com/id/ArduinoAndroid-Bluetooth-HC-06-Module-DHT11-Temp-M/

Qwiklabs: GCP & Kubernetes

LikeCoin

Arduino temperature and bluetooth wireless communication

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