On Wednesday 19th September 2018 was an introduction to microcontroller programming on the plan. Matej and the Slovakian student Marek were the responsible contact persons.
As microcontroller the ESP32 was available to us. As development environment we used the Arduino IDE with the programming language C++. This makes it very easy to control hardware. So we were able very quickly to celebrate our first small successes. So we could output text on a display, read the time from a real-time clock and make an LED blink.
On Friday, Marek's programming team was introduced to app programming.
At the beginning of the second week, we were able to really start programming, as the test boards for the microcontrollers were completely soldered. With Marek's help, we first created the coding for the ESP32. Here was the biggest difficulty to control the Bluetooth module. The communication between microcontroller and smartphone app is done via serialization. Here, strings are sent via the Bluetooth protocol, which can then be evaluated by the receiving device.
Then we wrote the app, with which we could access from the smartphone to the Bluetooth module of the ESP. For this we used Xamarin, which makes it possible to write the code in C #.
The app should be designed so that there are two pages. On the first page you had to connect to the Bluetooth device, so in our case with the ESP32. If this is done, you should go to the second page, with which you can control the LEDs of the house and where the temperature and humidity of the house are displayed. The most complex part of this was to treat exceptions, because in the communication between 2 Devices can lead to many errors.
On Thursday the second week then made small adjustments when the final version of the finished board was present.