16 Days in the Breeze – Wind Power Raspberry Pi / Arduino
It’s now been 16 days since I deployed the Project Curacao upgrades to the the Caribbean based box. The last 6 days look good. The first 4 days looked good, with some reboots of the Arduino Battery WatchDog from the SwitchDoc Labs Dual WatchDog Board. It went down from October 25th to October 28th, when I asked a friend to power cycle the box for me. Here is the RaspiConnect graph showing the computer being down:
Since October 28th, the box has preformed flawlessly. No reboots of the Arduino, no inappropriate reboots of the Raspberry Pi. Prefect recovery of the over night data from the FRAM in the WeatherPiArduino board installed in the Arduino Battery WatchDog. The new DS3213 RTC has been working exactly as designed (unlike the previous DS1307).
Wind Power Data Coming Soon
Now that I have a bunch of data, I’m now building a graph that will show the amount of power being generated by the Wind Turbine. I don’t think it is much!
What Happened During October 25-28th?
I have data. I can see in the couple of days before the 25th, there were a few reboots of the
Arduino during the day. At funny times, like 16:35 or 14:30. Always seemed to be around a time when the Arduino was likely talking to the Raspberry Pi via a serial interface. I first thought that I was spending too much time talking to the Raspberry Pi such that the external Dual WatchDog timer was expiring (over 200 seconds) but that didn’t seem likely.
Blame it on the RFI?
And then I talked to Geoff Howard, the king of the most famous Amateur Radio Ham Shack in the world (having won more worldwide Ham contests than another place in the entire world – PJ2T) who is graciously hosting the Project Curacao Box. He told me that there had been people getting ready and practicing for a contest on the 28MHz band last week and then ran the contest, 24 hours a day from Friday night October 24 until Sunday night, October 27th. When I compare the time period of the last to the previous 10 days, I see a pattern. Last 6 days, no problems (no transmissions at the site), shutdown for 3 days (during the contest!) then flakey for the week before the contest (when there were periodically people on the 28MHz band). Seems like a smoking gun to me. The box is not designed to protect from RFI in any kind of significant way (I ran out of time and the beach was calling my name). I’m going to ask the next visitors to at least put a choke on the line next to the box. If I miss a few interrupts now and again, that’s OK.
The wavelength of 28MHz radio waves is about 5 meters. I had a 15 meter line. Not a bad antenna for receiving 28MHz signals. Assuming that it is about 12 meters effective I have a nice 1/2 wavelength (2.5 wavelengths actually) staring at the input to the Arduino. And the WeatherRack (seen in the distance above) is connected directly to the tower where the 28MHz signal is being transmitted. Could be an issue, for sure. I have a question into the Radio Gods about what kind of voltages could I expect. One God has replied, saying up to 2V. That is pretty close to 2.5 Volts which will start triggering things.
The second God indicated that it could be all the way up to 3V and that there the contest last weekend was not just on 28 MHz. It was an all-band contest, on the 160, 80, 40, 20, 15, and 10 meter bands. During daylight hours on the contest weekend, transmitting will have been on 10m (28.3 – 29.0 MHz), 15m (21.2 – 21.4), and 20m (14.15 – 14.3 MHz). During nighttime hours on the contest weekend, transmitting will have been on 160m (~1.8 – 1.9 MHz), 80m (~3.6 – 3.9 MHz), 40m (~7.05 – 7.25 MHz) and 20m (~14.15 – 14.3 MHz).
Lots of little signals running around my box with the big new wire (antenna) connected.
Here is the RasPiConnect screen from a few minutes ago. Perfect behavior in all ways! Here’s a tutorial to build your own control panels using RasPiConnect. I have 5 Pages.
Of course, no posting from Project Curacao would be complete with our a picture from the Pi Camera, again on RasPiConnect.
