With PCB:

Programming your WeatherBot

The code for the project can be downloaded from GitHub: https://github.com/DIY-Machines/WeatherBot

I am finishing writing out the full instructions for this - it should be completed by 10th January 2022. Thank you for your patience.

There is a few changes you will need to make to the code downloaded from GitHub before uploading it to your WeatherBot. I'll guide you through them now step-by-step. This involves:

• Downloading Arduino IDE
• Adding an additional board manager and installing ESP32 boards
• Installing required libraries in the Arduino IDE
• Creating your own free account on OpenWeatherMaps
• Retrieving your own personal API key
• Entering your longitude and latitude
• Setting your desired ranges for weather
• Entering your own WiFi credentials

You may not need to complete all of the above steps - for example you may already have the Arduino IDE installed on your PC.

Downloading the Arduino IDE

The Arduino IDE is free software used for writing and uploading code to microcontroller boards. You can download it from the Arduino website here: https://www.arduino.cc/en/software

Download the appropriate version for your computer, either Windows, Linux or Mac and then follow the respective installers instructions.

Adding an additional Board Manager and Installing ESP32 Boards

Board managers allow us to add support for additional boards to the Arduino IDE. Before we can install the ESP32 boards we need to tell the Arduino IDE where it can find and download additional software.

Now that our IDE knows where to fetch a list of new boards we can open the Board Manager itself and install the ESP32 board.

Installing required libraries

Libraries are useful collections of pre-existing code which can quickly and easily add additional functionality to your programmes. There are a few which I have chosen to help develop this project. They are:

• Arduino_JSON by Arduino
• Adafruit GFX by Adafruit
• GxEPD2 by Jean-Marc Zingg
• ESP32Servo by Kevin Harrington and John K. Bennett

Download and open the projects code in the Arduino IDE

The code for this project is hosted on GitHub. Head to the project repository: https://github.com/DIY-Machines/WeatherBot

From the project page you click 'Code' and then 'Download Zip' to download the code to your computer. Open the folder which was download, followed by the 'WeatherBot' folder and then open the file 'WeatherBot.ino' in the Arduino IDE. This should also pull in the other files as tabs along the top of the IDE.

Create your own free OpenWeatherMaps account

Head on over to the sign up page at OpenWeatherMap and create yourself a free account: https://home.openweathermap.org/users/sign_up

Create your unique API key for the project

Once your account has been created you can log in to the OpenWeatherMap site again, click on your username in the top right and then 'My API Keys'

Type a name for the key which we are about to generate into the box on the right and then press 'Generate'.  I chose to call my WeatherBot. You should then take a note of the long Key it has generated for you. We will be adding this into the code in a few more steps before uploading it to your machine.

Finding your Longitude and Latitude

We let OpenWeatherMap know where we want to lookup a weather forecast for by passing them a longitude and attitude when we request the data. Head over to https://www.distancesfrom.com/Latitude-Longitude.aspx and use the tool on the page to find the longitude and attitude for the location whos weather you would like to monitor on your WeatherBot.

 It does not need to be where the WeatherBot itself is going to be. Note the location data down along with the API key from earlier.

Updating the code

The first part we can update is the SSID and Wifi password. This should be for the wireless network the WeatherBot will be connecting to in order to retrieve weather updates from the internet.

Lines #22 and #23 have placeholders where you should enter your Wifi credentials in place of "YOUR-SSID" and "YOUR-WIFI-PASSWORD". The speech marks ("") should remain around your own SSID and Password.

We make the weather data request by calling a URL with our specific API key, longitude, and latitude in it. We also include our unique API key which authorises or request and allows them to track how many requests we are making and how quickly.

At the time of writing this they currently allow 60 calls/minute with a maximum of 1,000,000 calls/month. More than frequent enough for our projects need.

Line #27 is where we store this URL / server path. The structure of it looks like:

http://api.openweathermap.org/data/2.5/onecall?lat={latitude}&lon=-{longitude}&units=metric&exclude=minutely&appid={Your-API-Key}

You need to replace the {latitude}, {longitude} and {Your-API-Key} sections with the values you noted down earlier. For example if mine were:

• API Key = f6dd3a936c3c156919f2364063685a9a
• Longitude = -2.4412
• Latitude = 50.7112

Then my URL / server path on line #27 would like this (all as one line):

http://api.openweathermap.org/data/2.5/onecall?lat=50.7112&lon=--2.4412&units=metric&exclude=minutely&appid=f6dd3a936c3c156919f2364063685a9a

Further down the code for the project their is a section which contains eight constant integers (lines #32 through to #45 - shown below) which determine how the WeatherBot interprets the weather and translates it to the pictorial form shown with the scene discs.

I've set the ranges based on how I feel with the weather in the UK, but this will likely need tweaking based on where you are based and how you personally find the weather. For example, 20°C is hot weather in my opinion here in the UK but elsewhere (such as Orlando, USA) 26°C may be more suitable.

The comments against each line in the code will give you guidance as to the unit of measurement used.



Uploading the Code to the ESP32

We can now connect our computer to the USB cable already connected to the ESP32 module. Then in the Arduino IDE select port and board type.

At the time of designing the WeatherBot and writing this tutorial there is a bug in the way the code is compiled for the ESP32 which prevents the e-ink display from functioning as intended. We can work around this by selecting the board type LOLIN D32.

You can then compile and upload the code to your WeatherBot. Don't forget to press the physical 'BOOT' button on the project itself whilst the Arduino IDE tries to connect after compiling the code.