After a couple of frustrating days trying to get the SPI interface to work, I ran across a post by Brett Wilson about using the shield with an I2C interface.
In his post he plugged the shield into a proto-board. I wanted to keep it attached to my FezPanda (.NET Micro, Arduino clone).
The attached PDF details the hardware mods to use the shield with the I2C interface. I will post NETMF C# code soon.
I’m finally getting around to working on the anemometer. I had originally planned on building an ultrasonic anemometer but finding a source for the transducers is proving to be quite difficult. Instead I’m going to build my version of a “rotorvane” anemometer (original can be found here).
Doing a bit of software development today. I have found an occasional error coming from the temperature / humidity sensor. It will sometimes output a value a few hundred degrees below actual temp. I’m working on an algorithm to trap and discard the bad data.
Here is a picture of my FARS.
I have looked around the internet and can’t find one like it. It seems to be working pretty well. Looks to have smoothed out some of the temperature errors I was having, but it needs to be tested a bit more and since today was overcast it needs to be tested on a hot, sunny day.
Yes, I know it looks like a space probe. The long bolts are only temporary until I get time to install the shorter ones I picked up at Lowes this evening.
Update: 5-20-11
I’m adding the design details of the Vertical Fan Aspirated Radiation Shield (pdf)
Parts list:
Qty — Description
1 – 10″ piece of PVC pipe, foam core pipe is best.
2 – 3″ Snap in drain inserts (Oatey)
1 – 3″ pipe coupler (used to join two pieces of pipe)
1 – 4″ PVC pipe cap
3 – 1/4″-20 Stainless steel bolts 3/4″ long
1 – Approx 80mm PC case fan
Start by trimming off the flange from one of the 3″ PVC snap in drains. This will be the Sensor mount.
Sensor mounted to the modified drain. Use the grid to zip-tie the cable.
Insert the modified drain into a piece of 3″ PVC pipe that has been cut to 10″ in length
Next mount the fan into the 3″ PVC coupler. Trim the corners to make it fit.
I glued it in place using some epoxy.
Now drill and tap 3 holes in the 4″ PVC pipe cap. These should be about 3/4″ up from the edge and spaced 120 degrees apart around the cap.
I used 1/4″-20 bolts.
Assemble the unit.
No PVC glue is required. Everything should fit tightly enough to not need it.
Put the modified drain and sensor about 2″ up inside the bottom end of the pipe.
Route the cable through the unmodified drain and insert it into the end of the pipe. Optionally add a round cutout of screen to act as an insect shield.
Next insert the pipe into the 3″ coupler on the side without the fan.
Next mount the 4″ pvc cap onto the coupler using 3 bolts inserted into the drilled and tapped holes.
there should by about 1/4″ gap all the way around the coupler/cap assembly. This is where the air exhausts.
The bolts should be tightened just enough to hold the assembly together. Too tight and you risk cracking something.
Mount the FARS as you see fit.
This wonderful little piece of metal helped me start off my day in a wonderful way.
It managed to embed itself in my tire all the way up to the little bolt.
Wow, less than one day. That is all it took for spammers to find this blog and start submitting comment spam.
I’m currently working on my weather station. This has been a work in progress for several years and I’ve finally taken the time to actually build it.
Currently it only has Temperature, Humidity, Barometer, and a partially working rain gauge.
The rain gauge is being problematic. It randomly has stay counts. I need to work on that next.