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SHT20 temperature sensor and Arduino example

In this example we will connect a SHT20 temperature sensor to an Arduino Uno. Lets look at some information about the sensor

The SHT20 humidity and temperature sensor of Sensirion has become an industry standard in terms of form factor and intelligence: Embedded in a reflow solderable Dual Flat No leads (DFN) package of 3 x 3mm foot print and 1.1mm height it provides calibrated, linearized sensor signals in digital, I2C format.

The SHT2x sensors contain a capacitive type humidity sensor, a band gap temperature sensor and specialized analog and digital integrated circuit – all on a single CMOSens® chip. This yields in an unmatched sensor performance in terms of accuracy and stability as well as minimal power consumption.

Every sensor is individually calibrated and tested. Lot identification is printed on the sensor and an electronic identification code is stored on the chip – which can be read out by command. Furthermore, the resolution of SHT2 can be changed by command (8/12bit up to 12/14bit for RH/T) and a checksum helps to improve communication reliability.

 

Parts List

 

Amount Part Type
1 Temperature and humidity detection sensor module SHT20
1 UNO R3 CH340G/ATmega328P, compatible for Arduino UNO R3

 

Schematics

Couldn’t find a good part for fritzing

Its an I2C device that needs 3.3v and GND, so its not that difficult to wire

 

Code

There is a library to make things easy and it is – https://github.com/DFRobot/DFRobot_SHT20

#include <Wire.h>
#include "DFRobot_SHT20.h"
 
DFRobot_SHT20    sht20;
 
void setup()
{
    Serial.begin(9600);
    Serial.println("SHT20 Example!");
    sht20.initSHT20();                                  // Init SHT20 Sensor
    delay(100);
    sht20.checkSHT20();                                 // Check SHT20 Sensor
}
 
void loop()
{
    float humd = sht20.readHumidity();                  // Read Humidity
    float temp = sht20.readTemperature();               // Read Temperature
    Serial.print("Time:");
    Serial.print(millis());
    Serial.print(" Temperature:");
    Serial.print(temp, 1);
    Serial.print("C");
    Serial.print(" Humidity:");
    Serial.print(humd, 1);
    Serial.print("%");
    Serial.println();
    delay(1000);
}

 

Output

Open the serial monitor and you should see something similar to this

SHT20 Example!
End of battery: no
Heater enabled: no
Disable OTP reload: yes
Time:203 Temperature:25.3C Humidity:48.6%
Time:1306 Temperature:25.2C Humidity:48.7%
Time:2410 Temperature:25.1C Humidity:48.9%
Time:3514 Temperature:25.1C Humidity:49.0%

Here is a video showing the code being compiled and the serial monitor being opened, I put my finger on the sensor to raise the temperature

 

Links

Sensirion_Humidity_Sensors_SHT20_Datasheet.pdf

 

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Arduino Uno and HDC1080 humidity and temperature sensor

The HDC1080 is a digital humidity sensor with integrated temperature sensor that provides excellent measurement accuracy at very low power. The HDC1080 operates over a wide supply range, and is a low cost, low power alternative to competitive solutions in a wide range of common applications. The humidity and temperature sensors are factory calibrated.

Features
Relative Humidity Accuracy ±2% (typical)
Temperature Accuracy ±0.2°C (typical)
Excellent Stability at High Humidity
14 Bit Measurement Resolution
100 nA Sleep Mode Current

 

Connection

This was connected an Arduino Uno

 Arduino connection  Module connection
 3v3 3v3
 GND  GND
 SDA – A4  SDA
 SCL – A5  SCL

 

Code

You will need to download the following library and install it from  https://github.com/closedcube/ClosedCube_HDC1080_Arduino , this is the default example

 

 

#include <Wire.h>
#include "ClosedCube_HDC1080.h"
 
ClosedCube_HDC1080 hdc1080;
 
void setup()
{
Serial.begin(9600);
Serial.println("ClosedCube HDC1080 Arduino Test");
 
// Default settings:
// - Heater off
// - 14 bit Temperature and Humidity Measurement Resolutions
hdc1080.begin(0x40);
 
Serial.print("Manufacturer ID=0x");
Serial.println(hdc1080.readManufacturerId(), HEX); // 0x5449 ID of Texas Instruments
Serial.print("Device ID=0x");
Serial.println(hdc1080.readDeviceId(), HEX); // 0x1050 ID of the device
 
printSerialNumber();
 
}
 
void loop()
{
Serial.print("T=");
Serial.print(hdc1080.readTemperature());
Serial.print("C, RH=");
Serial.print(hdc1080.readHumidity());
Serial.println("%");
delay(3000);
}
 
void printSerialNumber() {
Serial.print("Device Serial Number=");
HDC1080_SerialNumber sernum = hdc1080.readSerialNumber();
char format[12];
sprintf(format, "%02X-%04X-%04X", sernum.serialFirst, sernum.serialMid, sernum.serialLast);
Serial.println(format);
}

 

 

 

Output

Open the serial monitor window and you should expect to see something like this

T=21.75C, RH=28.00%
T=21.60C, RH=28.21%
T=25.36C, RH=32.17%
T=27.87C, RH=43.27%
T=27.42C, RH=40.23%
T=26.90C, RH=32.15%
T=26.41C, RH=27.84%
T=26.00C, RH=25.77%
T=25.59C, RH=24.80%
T=25.15C, RH=24.43%
T=24.81C, RH=24.34%
T=24.45C, RH=24.47%
T=24.13C, RH=24.68%
T=23.82C, RH=24.89%
T=23.55C, RH=25.30%
T=23.26C, RH=25.72%
T=23.01C, RH=26.14%
T=22.71C, RH=26.64%
T=22.49C, RH=26.96%
T=22.28C, RH=27.27%

 

Links

1PC 2.7 V to 5.5 V HDC1080 high precision temperature and humidity sensor humidity temperature module

http://www.ti.com/lit/gpn/hdc1080

http://www.ti.com/lit/pdf/snau189

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Arduino and LM75 temperature sensor example

The LM75 temperature sensor includes a delta-sigma analog-to-digital converter, and a digital overtemperature detector. The host can query the LM75 through its I²C interface to read temperature at any time. The open-drain overtemperature output (OS) sinks current when the programmable temperature limit is exceeded.

The OS output operates in either of two modes, comparator or interrupt. The host controls the temperature at which the alarm is asserted (TOS) and the hysteresis temperature below which the alarm condition is not valid (THYST). Also, the LM75’s TOS and THYST registers can be read by the host.

The address of the LM75 is set with three pins to allow multiple devices to work on the same bus. Power-up is in comparator mode, with defaults of TOS = +80°C and THYST = +75°C. The 3.0V to 5.5V supply voltage range, low supply current, and I²C interface make the LM75 ideal for many applications in thermal management and protection.

Key Features

SO (SOP) and µMAX® (µSOP) Packages
I²C Bus Interface
Separate Open-Drain OS Output Operates as Interrupt or Comparator/Thermostat Input
Register Readback Capability
Power-Up Defaults Permit Stand-Alone Operation as a Thermostat
3.0V to 5.5V Supply Voltage
Low Operating Supply Current 250µA (typ), 1mA (max)
4µA (typ) Shutdown Mode Minimizes Power Consumption
Up to Eight LM75s Can Be Connected to a Single Bus

 

Layout

I2C device you can power it from 3.3 or 5v

 

 

Code

I used this library – https://github.com/jlz3008/lm75

 

#define VERSION "1.1"
 
#include <inttypes.h>
#include <Wire.h>
 
#include <lm75.h>
 
TempI2C_LM75 termo = TempI2C_LM75(0x48,TempI2C_LM75::nine_bits);
 
 
void setup()
{
Serial.begin(9600);
Serial.println("Start");
Serial.print("Actual temp ");
Serial.print(termo.getTemp());
Serial.println(" oC");
delay(2000);
}
 
void loop()
{
Serial.print(termo.getTemp());
Serial.println(" oC");
delay(5000);
}

 

 

Links

LM75 temperature sensor high speed I2C interface high precision development board module

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Arduino and DS1624 temperature sensor

The DS1624 consists of two separate functional units: a 256-byte nonvolatile E2 memory and a direct-to-digital temperature sensor.

The nonvolatile memory is made up of 256 bytes of E2 memory. This memory can be used to store any type of information the user wishes. These memory locations are accessed through the 2-wire serial bus.

The direct-to-digital temperature sensor allows the DS1624 to measure the ambient temperature and report the temperature in a 12-bit word with 0.0625°C resolution. The temperature sensor and its related registers are accessed through the 2-wire serial interface. Figure 1 in the full data sheet shows a block diagram of the DS1624.

Features

Reduces Component Count with Integrated Temperature Sensor and Nonvolatile E2 Memory
Measures Temperatures from -55°C to +125°C in 0.0625°C Increments
±0.5°C Accuracy from 0°C to 70°C
256 Bytes of E2 Memory for Storing Information Such as Frequency Compensation Coefficients
No External Components
Easy-to-Use 2-Wire Serial Interface
Temperature is Read as a 12-Bit Value (2-Byte Transfer)
Available in 8-Pin SO and DIP Packages

 

Connection

Module Arduino
VDD 5v
Gnd Gnd
SDA SDA – A4
SCL SCL – A5

 

Code

I downloaded and imported the following library – https://github.com/bluemurder/DS1624

This is the example so some of the hard graft has already been done for you

#include <DS1624.h>
 
// Sensor presents all address pins connected to ground
DS1624 ds1624(0x00);
 
void setup()
{ 
// Begin serial connection at 9600 baud
Serial.begin(9600);
}
 
void loop()
{
float temperature;
bool valid;
 
// Get current temperature
ds1624.GetTemperature(temperature, valid);
 
// Print it
Serial.println(temperature);
 
// Wait a while
delay(1000);
}

Testing

Open the serial monitor and you should see the following

24.31
24.31
24.87
25.94
26.44
27.06
27.37
27.81
27.81
27.69

 

Link

https://datasheets.maximintegrated.com/en/ds/DS1624.pdf

CJMCU-1624 DS1624 temperature sensor, high precision digital thermometer with memory function

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