Guest Blog – Solar Powered OurWeather Station Part #2

February 13, 2017 ESP8266, Grove, OurWeather, Projects, SunAirPlus, SwitchDoc Products, Weather, WeatherPlus

Guest Blog – Larry Bonnette’s Solar Powered OurWeather Station #2Solar Powered OurWeather

 

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 make the Solar Powered 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 2 – Theory of Operation (How It All Works!)

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Figure 1

The weather station is now fully installed at our RC flying field in New Waverly Texas (Figure 1).

Looking at Figure 1. Do you see the thing that looks a little like a clock in the lower left hand corner of the photo? The WiFi access point is just below that “clock” behind the wall. I mention this because I think I am just at the edge of the WiFi reception range for the weather station. I measured this distance and it is approximately 10 feet. Keep this in mind for your installation.

I want to spend some time to explain how the weather station works internally as well as how we implemented it at our flying field.

Let’s look at the inside of the box again and use Figure 3 to step through the parts and talk about each device in more detail.

The board labeled “4” is part of the “OurWeather complete kit”. This board is called the “WeatherPlus – All in One Weather Station Controller”  This is a pretty sophisticated board whose job is to collect data from the weather sensors and communicate the data to the internet. The weather stations internet connection and the processing of the data coming from the sensors relies on a component on the board called an ESP8266. The ESP8266 is an Arduino based microprocessor that has built in Wi-Fi. This processor creates a miniature website that allows us to ask it (using a web browser) to send us weather data that was collected by the sensors.

If you would like to see the output from the now operational weather station visit https://tri-countybarnstormers.com/weathsta.htm

The WeatherPlus Board

Figure 2

Figure 2 is a close-up photo of the WeatherPlus.

The part labeled #1 is the rain bucket sensor input connector. It looks just like a telephone connector.

The part under #1 (it looks the same) is the wind speed and direction connector.

Part #2 is an I2C serial bus. Both of the connectors at #2 are identical and you can connect things to them interchangeably.  This bus is where you can connect a temperature probe and or an OLED display. Because it is a bus each component has an address and the microprocessor (#3) queries each component on the bus for information.

Part #3 is the ESP8266 80 MHz microcontroller with a full WiFi front-end and can be used as both a website and an access point. When the board first wakes up (I.E. it was never configured) it will show up in your computers list of Wi-Fi hot spots. You then use this feature to configure the WeatherPlus for your use. Also, notice the squiggly etched lines at the top of the ESP8266? Those lines are its antenna.

Part #4 is a mini USB connector and it is used to power the board using a USB cable. The WeatherPlus board also includes an onboard temperature sensor as well as a humidity sensor. We use this temperature sensor in the project to display the internal box temperature.

All the Boards Together

Refer to Figure 3 again. Notice that there is a USB cable coming out of the “WeatherPlus” (board #4) and it plugs into Board #2.

Board #2 is a USB power control board (included with the solar bundle). This board is used to control power going to the WeatherPlus board. LiPo batteries (item #1 in Figure 3) don’t like to be lower than 3.3 volts per cell. The USB power control board monitors the voltage on the battery and will power down the WeatherPlus board if the voltage level gets too low. It will keep the weather station “Off” until the battery is charged to a point that it can power the WeatherPlus board reliably. Notice there is a single orange wire coming from where the battery is connected to the Solar Plus board (#3) to the USB power control board. This wire is the sense wire and allows the USB board to measure the voltage on the battery. When the voltage on the battery falls to 3.3v, “Click”, the power is turned off. When the battery is charged to 3.8V, “Click”, the power is turned back on.

Continuing to refer to Figure 3 let’s talk about board #3. This is the SunAirPlus – Solar Controller. This is truly an interesting board. We use it in our project to simply charge the battery using solar cells and send the battery voltage level to the USB controller board. But this board does many more things. It even has the ability to track the sun. I encourage you to read more about this board on the SwitchDoc website.

Note the two white connectors at the bottom of the solar board. The right one is connected to the solar cells and the left one is connected to the battery. All of the circuitry between these connectors is used to charge the battery and send data via the I2C bus to the WeatherPlus board. This data includes charging details of the Solar and Battery systems. I present this data to users of the “Barnstormers” website (www.tricountybarnstormers.com).

At the top left side of the Solar board you see a cluster of four wires. This is the I2C bus connection. If you follow this cluster of wire to the right you will see that it goes to the I2C bus extender board (#5). The ESP8266 processor on the WeatherPlus board poles this bus and as it finds instruments on the bus that it recognizes it makes that data available over the Wi-Fi.

 

 

Next Up?

So, the question is; How exactly do we get the data off of the WeatherPlus board and display it to the end user?

In the last segment of this series, we will talk about how we extract and transmit the data from the weather station to the website and display it to the user in the final installment.

Thanks for your interest.