Tag:

temperature

A basic wemos temperature on OLED display example

by shedboy71 22nd February 2018

written by shedboy71

In this example we show how to connect multiple Wemos shields together to form more complex projects, in this example I use 4 shields. You can see a list of the shields and modules used below

Wemos Dual Base shield – a basic shield for connecting other shields and modules

Wemos D1 Mini : the basic ESP8266 module – there are 3 variants of this board

Wemos OLED shield : a 64×48 I2C OLED display which can display a few lines of text

Wemos DHT shield : a digital temperature and humidity sensor based on the DHT12 sensor

Code

2 libraries needed for this example

https://github.com/mcauser/Adafruit_SSD1306/tree/esp8266-64×48

https://github.com/wemos/WEMOS_DHT12_Arduino_Library

[codesyntax lang=”cpp”]

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <WEMOS_DHT12.h>

#define OLED_RESET 0  // GPIO0
Adafruit_SSD1306 display(OLED_RESET);

DHT12 dht12;

void setup() 
{
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
}

void loop() {
  
  // Clear the buffer.
  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.setTextColor(WHITE);

  if(dht12.get()==0){
    display.println("T: ");
    display.println(dht12.cTemp);
    display.println("H: ");
    display.println(dht12.humidity);
  }
  else
  {
    display.println("Error!");
  }
  display.display();
  delay(1000);

}

[/codesyntax]

Run this example and you will see the temperature and humidity displayed on the OLED display

Links

OLED Shield for WeMos D1 mini 0.66″ inch 64X48 IIC I2C for Compatible

Double Socket Dual Base Shield For WeMos D1 Mini NodeMCU For Arduino ESP8266 Development Board

WEMOS D1 Mini Pro – 16M Bytes External Antenna Connector ESP8266 WIFI IoT Board

DHT-Shield

22nd February 2018 0 comment

Arduino Sensors

Arduino and AM2302 humidity and temperature sensor

by shedboy71 5th July 2016

written by shedboy71

In this example we use the DHT22 (or AM2302) humidity/temperature sensor and the Arduino UNO board to read data and print it out to the serial monitor.

The DHT22 is better than the DHT11 because it has a wider range of measurement, 0 to 100% for humidity and -40°C to +125°C for temperature. Also it has a digital output that provides greater data accuracy.

I used a breakout , again it makes the job easier and doesn’t really add to the cost of a project

DHT22 Digital Humidity AM2302 and Temperature Sensor Module For Arduino

Breadboard layout

The resistor should be 4.7k in the layout below

dht22 breadboard layout

Code

Import the DHT11 library from Adafruit, in later versions of the Arduino IDE you can do this in the library manager. You can see this in the screenshot below

[codesyntax lang=”cpp”]

#include "DHT.h"
 
#define DHTPIN 6     // what pin we're connected to
#define DHTTYPE DHT22   // DHT 22  (AM2302)

 
DHT dht(DHTPIN, DHTTYPE);
 
void setup() 
{
  Serial.begin(9600); 
  dht.begin();
}
 
void loop() 
{
  // Wait a few seconds between measurements.
  delay(2000);
 
  float hum = dht.readHumidity();
  // Read temperature as Celsius
  float tempC = dht.readTemperature();
  
  // Check if readings have failed
  if (isnan(hum) || isnan(tempC)) 
  {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }     
  
  Serial.print("Humidity: "); 
  Serial.print(hum);
  Serial.print(" %\t");
  Serial.print("Temperature: "); 
  Serial.print(tempC);
  Serial.println(" *C ");
 
}

[/codesyntax]

Links

DHT22 Digital Humidity AM2302 and Temperature Sensor Module

http://akizukidenshi.com/download/ds/aosong/AM2302.pdf

5th July 2016 0 comment

Arduino Sensors

Arduino and SHT21 humidity and temperature sensor

by shedboy71 5th July 2016

written by shedboy71

Description

The digital SHT2x humidity sensor series is used in high volumes in a wide variety of applications and has today become the de facto industry standard. The SHT2x series consists of a low-cost version with the SHT20 humidity sensor, a standard version with the SHT21 humidity sensor, and a high-end version with the SHT25 humidity sensor. The open cavity mold package – which encapsulates the complete chip except for the humidity sensor area – protects the capacitive humidity sensor against external impact and facilitates excellent long-term stability.

Features

Size : 3 x 3 x 1.1 mm
Output : I²C digital, PWM, SDM
Supply voltage range : 2.1 to 3.6 V
Energy consumption : 3.2µW (at 8 bit, 1 measurement / s)
RH operating range : 0 – 100% RH
T operating range : -40 to +125°C (-40 to +257°F)

Its an I2C device so again is very simple to connect to any arduino

This is the breakout for the sensor that I bought, as you can see its a tricky part to use for the hobbyist, so a breakout makes like easier

Here is a simple schematic, again be careful as Vcc is 3.3v with this device

Schematic

SHT21 schematic

Lets look at the required libraries and a basic code example, there is not much to this to be honest most of the work is done in the library

Code

There are a couple of libraries to help you out

https://github.com/misenso/SHT2x-Arduino-Library
https://github.com/elechouse/SHT21_Arduino

I used the latter one

[codesyntax lang=”cpp”]

#include <Wire.h>
#include <SHT2x.h>


void setup()
{
  Wire.begin();
  Serial.begin(9600);
}

void loop()
{
  Serial.print("Humidity: ");
  Serial.println(SHT2x.GetHumidity());
  Serial.print("Temperature(C): ");
  Serial.println(SHT2x.GetTemperature());
  Serial.println();
  delay(1000);
}

[/codesyntax]

Links

these come in at about $7 for a useful breakout board with this sensor

SHT21 Digital Humidity And Temperature Sensor Module

5th July 2016 0 comment

Arduino Sensors

Arduino and DHT11 Temperature and Humidity Sensor example

by shedboy71 5th July 2016

written by shedboy71

Description

In this example we will show a basic example of connecting a DHT11 Temperature and Humidity Sensor to your Arduino. This is a very nice little, low cost sensor which requires only a pull up resistor to VDD. This can easily be constructed on a mini bread board and then joined up to your Arduino. using some connecting cables

The DHT sensors are made of two parts, a capacitive humidity sensor and a thermistor. There is a chip inside that does some a/d conversion and outputs a digital signal with the temperature and humidity. Again you can purchase the sensor and resistor seperately but I prefer to use a little module/breakout, there are many options available such as the one below

DHT11 temperature and humidity sensor module

I wont go into the technical details of the DHT11, there is a link at the bottom to a PDF datasheet which explains all you need to know.

Parts List

Label	Part Type
DHT1	DHT11 Humitidy and Temperature Sensor	
Part1	Arduino Uno (Rev3)
R1	4.7k Ω

Schematic

Arduino and DHT11 schematic

Breadboard layout

Arduino and DHT11 breadboard layout

Code

You will need either the DHT11 library from the DHT library. Download, extract and copy this to your Arduino libraries folder location.

In later versions of the Arduino IDE you can use the library manager and search for the DHT11 library from Adafruit and add it, you can see this in the screenshot below

dht11 library manager

This is a simple example which outputs the humidity and temperature, place a heat source such as your hand on the DHT11 and you will see the readings fluctuate

[codesyntax lang=”cpp”]

#include <dht11.h>

dht11 DHT;
//Pin 4 of Arduino to Data of DHT11
#define DHT11_PIN 4

void setup()
{
Serial.begin(9600);
int check;
Serial.print(“DHT11 STATUS – \t”);
check = DHT.read(DHT11_PIN);
//check status
switch (check)
{
case DHTLIB_OK:
Serial.print(“OK\n”);
break;
case DHTLIB_ERROR_CHECKSUM:
Serial.print("Checksum error\n");
break;
case DHTLIB_ERROR_TIMEOUT:
Serial.print("Timeout error\n");
break;
default:
Serial.print("Unknown error\n");
break;
}
}

void loop()
{

//humidity and temperature output
Serial.print(“Humidity is “);
Serial.print(DHT.humidity,1);
Serial.print(“\n”);
Serial.println(“Temperature is “);
Serial.println(DHT.temperature,1);

delay(1000);
}

[/codesyntax]
Output

Upload the sketch above and open the Serial Monitor window and you should see something like the following

Links
DHT11 Temperature And Relative Humidity Sensor Module
DHT11 Datasheet in PDF format

5th July 2016 0 comment

Arduino Code

Tick Tock Shield temperature example

by shedboy71 15th February 2016

written by shedboy71

Here is a picture of the Tick Tock Shield, this shield is ideal for beginners as it has several components such as a buzzer, LDR, LEDs, temperature sensor, buttons and 7 segment displays.

Tickshield

In this example we will get the temperature from the on board sensor, the sensor is connected to A0 and we will see the temperature via the Serial Monitor output

Code

[codesyntax lang=”cpp”]

#define TEMPERATURE_SENSOR 0

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  float temperature,resistance;
  int a;
  int B = 3975;
  a = analogRead(TEMPERATURE_SENSOR);
  resistance   = (float)(1023-a)*10000/a; 
  temperature  = 1/(log(resistance/10000)/B+1/298.15)-273.15;
  Serial.println(temperature);
  delay(500);
}

[/codesyntax]

Results

Open the serial monitor and you should see something like this

23.04
23.04
23.48
24.17
24.61
25.04
25.39
25.66
25.83
26.10
26.27
26.45
26.54

Links
1PC Real Time Clock Shield Digital Tube Module Thermal RTC TM1636 DS1307 For Arduino

15th February 2016 0 comment

Arduino Code

Esplora temperature example

by shedboy71 13th February 2016

written by shedboy71

This time we will use the on board temperature sensor of the Esplora and send the temperature out via the serial port, opening the serial monitor you will be able to read the temperature. You can see the sensor in the picture below

esplora

This example uses the readTemperature function

Description

Reads the ambient temperature of the temperature sensor and returns a reading in either the Celsius or Fahrenheit scale, depending on the parameter passed.

Syntax

readTemperature(scale)

Parameters

scale: the scale of the output, valid arguments are: DEGREES_C and DEGREES_F

Returns

int : The temperature reading in Celsius or Fahrenheit. The Celsius range is from -40°C to 150°C, the Fahrenheit range is from -40°F to 302°F.

Code

[codesyntax lang=”cpp”]

#include <Esplora.h>

void setup()
{
  Serial.begin(9600);
} 

void loop()
{
  int celsius = Esplora.readTemperature(DEGREES_C);
  int fahrenheit = Esplora.readTemperature(DEGREES_F);
  Serial.print(celsius);
  Serial.print("\t");
  Serial.print(fahrenheit);
  Serial.println();
  delay(1000);
}

[/codesyntax]

Results

Open the serial monitor and you will see something like this

19 69
20 69
20 69
21 69
20 69
20 69

13th February 2016 0 comment