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tempsensor



Description:
First public release: tempsensor-1.0 - 27-02-2002

Tempsensor is a simple FreeBSD program to interface with a Sensirion SHT11
sensor.
The sensor must be hooked up to the parallel port.

The program simply spits out two values: Temperature and Humidity.


Connect the SHT11 sensor to the parallel port as shown in this table :
Parallel port pinDescriptionSHT11 pin
20 to 25Groundpin 1
14Data outConnected via a diode to pin 2 *
15Data inpin 2
16Clockpin 3
9 to 11Positive supplypin 4 **

*
The data output pin of the parallel port should poll the data-line low, but not push it high. Otherwise the SHT11 would not be able to pull the data-line low.
So the anode of the diode is connected to pin 2 of the SHT11 and the cathode is connected to the parallel port. Any diode (e.g. a 1N4148) will do

**
I used the power of 3 data-bit's of the parallel port to power the SHT11.
You could also choose to power it with an external 5V power supply.

Circuit diagram
The entire circuit diagriam I used to connect the sensor looks like this :
Circuit diagram SHT11 interface


Releases:

tempsensor-images
tempsensor-1.0



Email me with questions/comments : Daan <Daan @ pa4dan . nl>