0 Replies Latest reply on Oct 2, 2018 7:49 PM by user_13463998

    I2C Temperature and Humidity Sensor (SHT31)

    user_13463998

      One day, the ad of this sensor appeared on my web browser again and again.

      When I read the description it seemed to be interesting, so I ordered my Digi-Key account a couple of this sensors.

      The price of the sensor was about $9.00, so $18.00 for two, but the shipment costed me more than that.

      A few weeks later, at Akizuki in Akihabara, I found a module of this sensor being sold about $9.00.  orz

       

      Anyway, I wrote a simple test program for this, the hardest part was calculating the CRC value.

       

      IMG_2797.JPG

       

      I used MSS (Marubun Sensor Shield) to provide I2C signal pull-ups.

      I could have used a couple 10K resistors, but this was easier.

      (Refer to the schematic below)

       

      SHT31.JPG

      Since the sensor is connected via I2C, SDA and SCL must be pulled up.

      And I connected the PIN 4 (ADR) of SHT31 to GND, so the slave address is 0x44.

       

      TeraTerm_log.JPG

      At the first loop, since the register values were not assigned the result were 0x0000 and 0xFFFF.

      But from the second loop, the sensor reports reasonable values.

       

      moto