This is the continuation of my journey through the ELL-i Hackathon. You can also read part 1.
Back to work, the final part was to connect the whole circuit back to the ELL-i board, to an Analog-to-Digital converter that could read the received voltage and adjust the circuit to keep it always around 12 Volts. This was the “feedback loop” and it had to receive an even lower voltage for the board to be able to read it. There were more resistors, diodes and condensers to put in the circuit, but I was lacking space. I put a new protoboard, connected some wires to make it part of the original one and kept going. After a few hours of testing, connecting things and checking with the voltmeter it seemed ready to be connected to the ELL-i. I put the cable, but nothing was happening… Where was the problem now?
I connected to the serial monitor of the ELL-i board and noticed that weird numbers were appearing, as if the cable would have been in the air. I double checked my protoboard and there I found the reason: I had inserted the cable in the wrong row, so it was indeed in the air. I changed it to the correct row on the protoboard and everything looked fine. I connected again to the ethernet cable with power, and there was no smoke. The last test was coming: I put the voltmeter and I had a steady 12 volts on the point where the Power LED had to go. All set! I finally connected the power LED, put the ethernet cable in the ELL-i and the light turned on!
My complete circuit connected to the ELL-i board
I was able to complete the workshop with a very little background in electronics, and it was a great experience. It increased my confidence in being able to interact with the environment using a computer system, in this case a board like ELL-i and I learnt that by using power-over-ethernet solutions I can power things, like a light, with only one cable and also be able to interact with the environment through sensors and in the future also with the internet. Smart Spaces was now at my fingertips!
I had a lot of fun in the workshop, learnt many new things and met nice people, so if you have the opportunity to participate in one, don’t miss it!