SHT1X

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Introduction

SHT-11.jpg

The SHT1x is a precise temperature / relative humidity sensor made by Sensirion.

  The SHT1x uses it's own protocol. Be aware: On first sight it looks like an I²C but it is not compatible to I²C.

The types SHT10, SHT11 and SHT15 only differ in accuracy (and price, obviously).

Typical accuracy (From Sensirion SHT1x datasheet)

  SHT10       ±4.5% rH      ±0.5 °C
  SHT11       ±3.0% rH      ±0.4 °C
  SHT15       ±2.0% rH      ±0.3 °C

Precautions

The SHT1x runs well on 3.3V so no level shifter or special power supply is needed.

The bare circuit is very small and difficult to handle and solder. There are small printed circuit boards (PCB's) on the market making the handling much easier as they keep the needed resistors and capacitors too.

SHT-1X on PCB.jpg

SHT-1x-PCB-Pinout2.jpg

SHT1x-Pinout.jpg

The SHT1x should not be used without protection against dust and condensing water. Several cases for these sensors are in the market, some examples shown in the pictures.

Protective Case1.jpg

Protective Case2.jpg

An example for a completely mounted SHT-1x:

SHT-1X Mounting Example.jpg

Hardware

Connecting the SHT1x is easy. Just connect it as shown in the schematic, including the resistors and the capacitor. The capacitor should be placed as near as possible to the sensor.

  SHT1x		ESP
  GND		GND
  VCC		3.3V
  DATA		D6(GPIO12)
  SCK		D7(GPIO13)


SHT1x-Schematics.jpg

ESPEasy

Set up the ESPEasy task according to the screenshot.

SHT1x Settings.jpg

Submit your settings. After some seconds the tasklist will show like this:

SHT1x Tasklist.jpg

If it shows all values as zero, don't worry. Wait a minute and refresh the browser page.

Calibrating

See "Basics: Calibrating" for further information

[1]

Your SHT1x shows deviating values

This might have several reasons.

At first: Voltage regulators and the ESP8266 itself produce some heat. This influences the temperature and humidity values of the sensor. Put the sensor as far away from the circuits, if possible outside the case.

All sensors have their own tolerances. On top the analog to digital conversion produces a deviation of about ±1...2 digits.

It is possible to calibrate sensors using a formula See "Basics: Calibrating" for further information

[2]

Last but not least problems with the power supply are quite widespread. See "Basics: Taming false positives" in the wiki for info about filtering power supply.

[3]

Optional settings

Use of formulas

Use of value names