28018 Parallax

599 Menlo Drive, Suite 100 General: info@parallax.com Rocklin, California 95765, USA Technical: support@parallax.com Office: (916) 624-8333 Web Site: www.parallax.com Fax: (916) 624-8003 Educational: www.stampsinclass.com Sensirion SHT11 Sensor Module (#28018) Precision Temperature and Humidity Measurement Introduction When it comes to precision temperature and humidity measurement, Sensirion (www.sensirion.com) has simplified the process their SHT1x sensor series. Through a two-wire serial interface, both temperature and humidity can be read with excellent response time and accuracy. Parallax has simplified the use of the SHT11 by mounting it in a user-friendly 8-pin DIP module. The module includes a data-line pull-up and series limiter making it possible to connect directly to the BASIC or Javelin Stamp. Features Temperature range: -40 F (-40 C) to +254.9 F (+123.8 C) Temp. accuracy: +/- 0.5 C @ 25 C Humidity range: 0 to 100% RH Absolute RH accuracy: +/- 3.5% RH Low power consumption (typically 30 W) Connections The SHT11 is interfaced to the Stamp over two I/O pins. The 4.7 k pull-down resistor on the clock is optional but may be required if your application experiences sensor lock-up. Vdd SHT11 Sensor Module 330 4.7 k Data 1 8 2 SHT11 7 Clock 3 6 4 5 4.7 k Vss Vss Parallax, Inc. Sensirion SHT11 Sensor Module (#28018) 07/2003 1BASIC Stamp Application The following BASIC Stamp application will read the SHT11 sensor module and display sensor counts, converted temperature and calibrated humidity. When running, the program output will appear as shown below: ' ========================================================================= ' ' File...... SHT11_Demo.BS2 ' Purpose... Interface to Sensirion SHT11 temperature/humidity sensor ' Author.... Parallax ' E-mail.... support@parallax.com ' Started... ' Updated... 19 JUL 2003 ' ' {$STAMP BS2} ' {$PBASIC 2.5} ' ' ========================================================================= ' ------------------------------------------------------------------------- ' Program Description ' ------------------------------------------------------------------------- ' Parallax, Inc. Sensirion 2 SHT11 Sensor Module (#28018) 07/2003