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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 pin | Description | SHT11 pin |
| 20 to 25 | Ground | pin 1 |
| 14 | Data out | Connected via a diode to pin 2 * |
| 15 | Data in | pin 2 |
| 16 | Clock | pin 3 |
| 9 to 11 | Positive supply | pin 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 :
Releases:
tempsensor-images
tempsensor-1.0
Email me with questions/comments : Daan <Danovitsch @ Vitsch . net>