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Makahiya – Power supply, LEDs and other

Hi everybody,

On Friday, we managed to find answers to some our questions thanks to Arnaud, Alexis and Samuel.

First, on the LEDs: Arnaud helped me finding why the most powerful LEDs seemed to be less bright than the others. The reason was that, contrary to what we thought, the pins that was supposed to provide power the LEDs was in fact not connected to +5V but a GPIO… And, according to Alexis’s advice, I checked my resistors values and it appeared that I calculated them with the “typical” values given in the datasheet and not with the “maximum” ones. After having correcting these 2 problems, the most powerful LEDs showed their whole power. Some smoke even appeared… So now, we think that we’ll choose the other LEDs. Alexis has ordered optical fiber and also the lightning kit from Luxeum. Consequently, on Wednesday, we’ll be able to completely test our LEDs and confirm (or not) our choice.

For the micro-processor: We’ll keep the 64-pins version, which is enough for us.

Alexis also told me what connectors to choose in order to plug the power supply and the Flexinol, and I also have to change the transistors I use to smaller ones. I’ve selected them and I will add them in the electrical schematic as soon as Alexis validates my choice and creates them in the library of Expedition PCB.

The electrical schematic is almost ready now. We just need to add the LEDs part, which will be done after next Wednesday tests. I took care of the clock part Friday afternoon.

I’ve also tested the capacitive touch sensor with the internal clock to see if an external one was needed, and the internal one is far enough for us.

Between now and Wednesday, I will take care of the code able to detect touches on leaves with the capacitive sensor. And on Wednesday, I’ll test the optical fibers.

That’s all for today.

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