Guest Blog – Larry Bonnette’s Solar Powered OurWeather Station #1

Editors Note:  We were tickled to receive this guest blog by Larry Bonnette.   He did a great job on building this Solar Powered OurWeather Kit and by adapting the GroveWeatherPi solar panel kit to the OurWeather Kit.   FYI, SwitchDoc Labs is releasing a Solar Power Kit tailored for OurWeather in the next couple of weeks.

This is a three part series about building this weather station for the Tri-county Barnstormers RC Club.

• Part 1 - Building the Box
• Part 2 - Theory of Operation (How It All Works!)
• Part 3 - Webpages - Transmission and Display of the Results

Part 1 – Building the Box

I am a member of the Tri-county Barnstormers RC club near Houston Texas (www.tricountybarnstormers.com). Just before Christmas 2016 I designed and installed a video camera system to allow members see who is at the field in New Waverly Texas (https://tri-countybarnstormers.com/field_cam.htm).  The camera was a great success but members also wanted to know the current weather.  I explored the possibility of using Weather Underground and this worked for a while.  But, members noticed that the reported wind speed did not match the current wind speed at the field.

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The solution was to place a dedicated weather station right at the field.

I searched the internet for a solution specifically something that utilized a Raspberry Pi. This search led me to Switchdoc.com and their “OurWeather complete weather kit”. It was perfect for the job.

At just under $150 it was Wi-Fi ready so we didn’t have to run any wires to get the data to our web site and came with all of the sensors and most of the mounting hardware necessary.

But, what about power? I studied the requirements of the “weather station” and found that SwithDoc.com also had a complete solar bundle called the “GroveWeatherPi Solar Add-on Product Bundle”. This bundle was designed for the Raspberry Pi but I figured that it would probably work on the “OurWeather” with a little tweaking.

I asked Santa for both the weather station and the solar bundle and was thrilled to see it under the tree on December 25^th.

Now that I have all of the components for the weather station to be install at the flying field. How exactly would I fit it all together?

SwitchDoc.com has a lot of examples of just what I needed right on their web site. So, I decided to use their Pi based weather station example and modify it to be used with the OurWeather station.

I would use a weatherproof box and mount all of the electronics inside. The box will attach to a pole using “U” bolts and will be located on the East side of the flight pavilion so that Its solar panel can take advantage of the sun to charge a 3V 4400mah LiPo battery.

SwitchDoc.com provided 3D printer models to be used with the mounting of the solar panels but I was not happy with the way it held the panels. So, I designed and printed my own version.

I did, however, use the 3D model of the temperature probe cover that is on their website and mounted it on the back of the box.

The Box and the Mounting

So, let’s start with the box. I got it from Amazon https://www.amazon.com/gp/product/B007EWXC02/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

It is an “Impact Line Enclosure, Integrated Latch, Mounting Flange, 9″ Height, 8″ Width, 2.45″ Depth” (Figure 1) I got one with a

flange because I knew I wanted to mount it to a pole and I could use “U” bolts through the flange (Figure 2).

The Electronics Inside

Click here for a large version of Figure 3.

I was not sure how I could mount the 4 boards and the battery in the box and I finally decided to fasten them to the inside of the box with “Servo Tape”. Figure 3 shows the placement of the boards:

1. #1 – Is the 4400 mha LiPi 3.7 v battery Purchased from Adafruit.com. It is connected to the “Solar Plus” board.
2. #2 – Is a USB power board (USB PowerControl). This board is used to turn off the power going to the OurWeather board (number 4) when the battery gets too low. This board is included in the “Solar Bundle”
3. #3 – Is the SunAirPlus  board (included in the “Solar Bundle”). It is used to charge the battery with solar energy and supply power to the “OurWeather” board. The OurWeather board also sends data about the solar charging system to the “Barnstormer” website.
4. #4 – Is the “OurWeather” board. It receives input from the weather sensors (wind,temperature,humidity etc) and sends it wirelessly to our website.
5. #5 – Is a connection expander (included in the Weather kit). There are not enough connection points on the weather board so this adds more.
6. #6 – Is an OLED display (included in the weather kit) that shows weather data. It is displayed on the outside of the box.
7. #7 – Is the cable coming from the temperature probe (included with the weather kit) mounted on the outside of the box.
8. #8 – Are the wires coming from the solar cells (included with the solar bundle and wired in parallel) and connects to the “SunAirPlus” board.

The solar panels are 6V 330ma cells. Three cells are provided in the “Solar Bundle” The cells are wired in parallel which then provide 990 ma at 6V to charge the 3.7 volt LiPo battery. The charging of the battery is all taken care of for you by the SunAirPlus board. This board also boosts the 3.7V battery voltage to 5 volts and sends it via the USB connector to the weather station which runs on 5v.

The Solar Mount

The panels are fastened to the outside of the box using the 3D printed Solar Panel mount (Figure 4 and 5) that can be found on Thingiverse.com   https://www.thingiverse.com/thing:2077079 (Editors Note:  We just published an article about this new mount here and we are using this mount in Project Curacao 2.   This is much better mount than the one we designed – but takes a lot longer to print.  Since ours is going to be 3500 miles away and in the hot sun, Larry’s is worth it!)

I haven’t mounted the weather station at the field yet because I needed to re-design the tilt braces for the solar mount. Here they are being printed (Figure 6).

And here they are mounted to the box (Figure 7).

Next Up?

Part 2 with the Theory of Operation (How it all Works!)