Print PDF
Favorite
Email
Problem: So I’ve been taking walks with my dog, Marcus and my Arduino pedometer.
http://www.instructables.com/id/Arduino-Pedometer/
Out here in the high desert in January, it gets cold and a little wind creates a cold wind chill factor. I’m a LAZY OLD GEEK and would like to know what the wind chill factor is.
Solution: I’ve always wanted to build a weather station so I decided to make an Arduino wind anemometer to measures wind speed and a thermometer. An instrument that measures wind speed is called an anemometer. Then the Arduino can calculate wind chill.
Wikipedia Definition: Wind chill (often popularly called the wind chill factor) is the felt air temperature on exposed skin due to wind. It measures the effect of wind on air temperature.
LAZY OLD GEEK ‘facts’: Any object, e.g., a car is not affected by wind chill. If the temperature is 10F, it doesn’t matter if the wind chill is 10F or -40F. Wind chill is the apparent temperature felt by humans and animals. Or I should say some animals. My dog, Marcus has a nice fur coat and is part husky. He doesn’t feel it. He doesn’t care if it’s -40F wind chill and seems to prefer it. Now, I, on the other hand won’t venture out if the wind chill is -40F. But if it’s -10F, I might wear my full face mask (see picture) and venture out. I don’t like to wear it because it’s uncomfortable after a while so it’s helpful to know what the wind chill is.
So that’s not a great reason to build a wind chill machine but I’ve always wanted a weather station and this is a good starting point. My weather station is designed for the U.S., so I use Fahrenheit and MPH.
Attention Readers: If you want to duplicate this project, you will need a laptop with a USB port and a motor vehicle to calibrate the wind speed. Another problem is finding the cups for the anemometer. Many Instructables readers seem to be good at improvising. Aluminum is preferred but plastic should work also. For the innovative readers, I’ve provided some hardware and software tips on how to design your own anemometer. For example, the software could be adapted to an LED or LCD display for a standalone instrument.
http://www.instructables.com/id/Arduino-Pedometer/
Out here in the high desert in January, it gets cold and a little wind creates a cold wind chill factor. I’m a LAZY OLD GEEK and would like to know what the wind chill factor is.
Solution: I’ve always wanted to build a weather station so I decided to make an Arduino wind anemometer to measures wind speed and a thermometer. An instrument that measures wind speed is called an anemometer. Then the Arduino can calculate wind chill.
Wikipedia Definition: Wind chill (often popularly called the wind chill factor) is the felt air temperature on exposed skin due to wind. It measures the effect of wind on air temperature.
LAZY OLD GEEK ‘facts’: Any object, e.g., a car is not affected by wind chill. If the temperature is 10F, it doesn’t matter if the wind chill is 10F or -40F. Wind chill is the apparent temperature felt by humans and animals. Or I should say some animals. My dog, Marcus has a nice fur coat and is part husky. He doesn’t feel it. He doesn’t care if it’s -40F wind chill and seems to prefer it. Now, I, on the other hand won’t venture out if the wind chill is -40F. But if it’s -10F, I might wear my full face mask (see picture) and venture out. I don’t like to wear it because it’s uncomfortable after a while so it’s helpful to know what the wind chill is.
So that’s not a great reason to build a wind chill machine but I’ve always wanted a weather station and this is a good starting point. My weather station is designed for the U.S., so I use Fahrenheit and MPH.
Attention Readers: If you want to duplicate this project, you will need a laptop with a USB port and a motor vehicle to calibrate the wind speed. Another problem is finding the cups for the anemometer. Many Instructables readers seem to be good at improvising. Aluminum is preferred but plastic should work also. For the innovative readers, I’ve provided some hardware and software tips on how to design your own anemometer. For example, the software could be adapted to an LED or LCD display for a standalone instrument.
Remove these ads by
Signing UpStep 1Parts List
Here’s a list of the parts I used:
USB Freeduino kit (Arduino-clone) $22.50
AdaFruit DIY shield $6.00
PVC
1/2” right angle
1/2” T
10 feet 1/2” PVC
2” PVC end cap
Hardware
5-16 x 3” bolt
5-16 nuts and washers
8-32 x 4” bolts
8-32 nuts and lock washers
2 small magnets (10 for $1 at Harbor Freight)
1 Inline skate bearing(Size 608Z)($1.36@)
3 Aluminum balls SuperBubble, LemonHead
Honeywell SS461C Hall Effect IC($1.86 Digikey)
50 feet Telephone cable ($3.00 4 or 6 wire)
1 MCP9701 Temperature sensor($0.30 DigiKey)
2 telephone couplers ($1.00@ dollar store)
Prices US dollars February 2011
The total is about $15 plus Arduino stuff.
Tools:
Soldering tools
DMM Recommended
Drill/drill press
Socket wrenches
USB Freeduino kit (Arduino-clone) $22.50
AdaFruit DIY shield $6.00
PVC
1/2” right angle
1/2” T
10 feet 1/2” PVC
2” PVC end cap
Hardware
5-16 x 3” bolt
5-16 nuts and washers
8-32 x 4” bolts
8-32 nuts and lock washers
2 small magnets (10 for $1 at Harbor Freight)
1 Inline skate bearing(Size 608Z)($1.36@)
3 Aluminum balls SuperBubble, LemonHead
Honeywell SS461C Hall Effect IC($1.86 Digikey)
50 feet Telephone cable ($3.00 4 or 6 wire)
1 MCP9701 Temperature sensor($0.30 DigiKey)
2 telephone couplers ($1.00@ dollar store)
Prices US dollars February 2011
The total is about $15 plus Arduino stuff.
Tools:
Soldering tools
DMM Recommended
Drill/drill press
Socket wrenches
| « Previous Step | Download PDFView All Steps | Next Step » |
The way-too-high or -low temp readings you're getting might be from the sensor exposing to direct sunlight or too much wind. I've made dozens of thermometers using the LM35 series of Temperature sensors by National and I've noticed when the sun shines on the sensor, no matter how cold the air is, the reading goes up abnormally high. The same when the wind blows over the sensor. I've had readings of 50°C in a fresh (16°C) morning when the sun rises and reaches the sensor. Heat reflection also gives these readings. I had a sensor 2 yards from a sun-bathed wall and the thermometer went up to 36°C in a 20°C day. Sometimes the error is corrected encapsulating the sensor in white heat-shrink tubing. Maybe painting the sensor white works too.
Nice anemometer indeed!
http://www.instructables.com/id/Arduino-Weather-Station-Part2/
http://www.instructables.com/id/Arduino-Weather-Station-Part3-Rain/
I don't think my readings are related to sun or wind. The ones I've noticed are just one sample where the one before and after seem to be okay so I suspect that it's either an intermittent connection or glitches in the serial communications. However since they don't happen very often and it's just for my personal use, I pretty much ignore them.
I usually leave it running 24/7. Occasionally, the Arduino stops communicating all together and I have to reset it.
And once, I had to replace the Atmega chip. I'm fairly certain it was lightning.
LOG
Lazy Old Geek
Here in Argentina the summer has been a little hot. 43º of thermic sensation in my zone, that is not one of the hotter. And the meteorological service threaten us with more heat during frebruary!
There's actually another thing called heat index which is the counter part of wind chill. I was thinking about adding that feature but our summers are pretty dry so don't know if it would be worth it.
Lazy Old Geek