Wireless Weather Station Project: Week 4 (27th Feb 2015)

Week 4 (27th Feb 2015)
This is the forth week of the wireless weather station project.
The main progress of the lab day was divided into two parts. One was on detecting the signal types of the wind direction and wind speed and the other was programming.

Detect signal types

To achieve this task, the outside sensor from WH1081 is taken apart as photo shown below:

According to the photo, the above one is wind speed sensor whose inside chip is as:

There are 8 switches connected with 8 resistors in the circuits whose resistor values are measured and specified by group members. The representing circuit is shown in figure below:

In terms of the signal type that wind speed sensor sends, it has been clarified that every 120 degrees the outside jacket rotates, it would generate a digital pulse signal. It means that every time the sensor makes a round, three digital pulses will be sent.

Seen from the first photo, the sensor below is the one for wind direction whose inside chip is like:

It has been found out that there is a magnet in the shell. Due to the magnetic connection between the shell and chip, the direction sensor has the ability to sense changes of wind direction and then generates analog signals.