Nuts & Volts - June 2007

hour settings are stored into the DiosPro built-in EEPROM. This means if you reset the chip or have a power failure, you won’t lose your prediction data.

History

All the sensors have been added. Now let’s add a bit more processing.

PARTS LIST

EarthLCD

❑ ezLCD001 http://store.earthlcd.com/LCD?sc= 7& category=297

HOBBY BOARDS

❑ DS18S20 1-Wire Temperature Sensor www.hobby-boards.com/catalog/prod uct_info.php?cPath= 26&products_id= 93

❑ Barometer Module (B1-R1-A) — www. hobby-boards.com/catalog/product_ info.php?cPath= 22&products_id=36

❑ Humidity Module (H3-R1-A) — www. hobby-boards.com/catalog/product_ info.php?cPath= 22&products_id= 46

❑ AAG Weather Instrument — www. hobby-boards.com/catalog/product_ info.php?cPath= 22&products_id= 92

SPARK FUN ELECTRONICS ❑ SCP1000 www.sparkfun.com/commerce/prod uct_info.php?products_id=8161

KRONOS ROBOTICS ❑ DiosPro 40 chip www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16168

❑ DiosWorkboard Basic

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June 2007

Load up the file called LCDweather6.txt. Take

a close look at the program. I have a new set of functions called calchistory. All the sensors that we have added use global variables to store their readings. The calchistory function takes the temperature, humidity, and average wind speed and plots them on the graph once per hour, as shown in Figure 22. This way, the last 24 hours are shown. In addition to the display, these readings are stored in the DiosPros EEPROM so that if we have to reset the chip, we won’t lose the graph information.

■ FIGURE 23

Final Thoughts

We covered quite a bit of material in this article. I understand that many of you will want to build

www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16453

❑ 14V DC Adapter www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16500

❑ 36-Pin Female Header www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16291

❑ 40-Pin Male Header www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16290

❑ TO-220 Heatsink www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16250

❑ 1K Resistors www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16178

❑ Expanded PVC 5x7 www.kronosrobotics.com/xcart/cus tomer/ product.php?productid=16432

❑ Free Dios Compiler (Includes ezLCD and 1-Wire libraries) — www.kronos robotics.com/downloads/DiosSetup.exe

OTHER

❑ RJ11 Surface Mount Box — I used a GE TL26101. Can be purchased from most home centers.

a custom weather station and may not be using the exact sensors that I have used here. I will be glad to answer any of your questions to help you make your modifications. Please use our Weather Center and Home automation forum at www.kronosrobotics.com/forums/ viewforum.php?f= 25.

There is plenty of unused space on the ezLCD display. In the future, I will be adding a rain gauge, as well as moisture and various other sensors.

I have been experimenting with the SCP1000 available from Spark Fun Electronics shown in Figure 23. This is one accurate pressure sensor and can track barometric pressure to three decimal points. It’s faster and more accurate than the 1-Wire sensors. It also has an onboard temperature sensor. This particular model uses a two-wire I²C interface and a complete Dios library is available. If you decide you want to use one of these, check out the application note on the Kronos robotics website at www.kronos robotics.com/Projects/SCP1000. shtml.

What’s Next

Next month, I am going to look at adding a couple remote Zigbee units to the sensors on our weather pole. This will make our weather station truly portable.