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Makahiya – server, capacitive sensor and Wi-Fi

Hi everybody,

The beginning of this week has been quite productive. Indeed, I managed to have different tasks reaching a functional state.

First, I worked on the server. I added several pages to provide an interface that allows the user to trigger all the actions that the plant can perform. I also improved the login/logout functionality. For the front-end, after some discussion with my classmates, I chose to use Bootstrap. It allowed me to have an acceptable-looking website in a short time.

On Tuesday, we received the new FDC evaluation board (for the capacitive sensor). This time, I connected the pins very carefully, entirely reviewed my code and tested it. After some minor correction, I was able to configure the sensor and to read data by polling it. After that, because polling is a bad thing and that in that case, it can be avoided, I implemented the part of the driver that waits for an interrupt (that signals that a new set of data is available). With this, the driver seems operational to me. Next step will be to connect it with the detection algorithm I wrote a few months ago.

Finally, I also worked on the Wi-Fi module. I greatly improved the websocket part of the driver and after the corrections made by Tanguy on the server side of the websockets, it worked very well. Like with the capacitive sensor, it was done by polling the module. And in this case also it was possible to avoid it by using an interrupt. So I tried to implement this part of the driver. I had some problems to find a pin on which the pulldown resistor worked (because on the 2 first  I tried, there was a pull-up somewhere on the board…). And I had also some (stupid) mistakes on my code that make me lose some time. But it forced me to carefully review my code and thus to improve it, so it’s been useful. So now, websockets are fully operational. I also improved a lot the management of the errors and started to implement the decoding of the commands that will be received through the websocket. As one of these commands is to play a music downloaded from the server, I tried to re-use the code I’d already written for this. And the last error re-appeared unfortunately: the Wi-Fi module takes too much time to answer to my requests. And I don’t have any idea of possible origins of this problem. I will try tomorrow with another Wi-Fi network to see if it changes something, but I don’t hope too much.

The end of the week will be dedicated to solving the problem with the music and to connect the detection algorithm with the capacitive sensor driver: assembling several parts together in fact. It’s the beginning of the integration phase and this is a good news.

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