Notes:
The next step will be to add mesh-networking capabilities by sending a broadcast packet and waiting for the reply from the others nodes, and create a table of reachable nodes.
It would be nice to add some randomness in the delays of transmission otherwise we will only receive packets from nodes emitting at a precise moment.
Also, at the moment the packets are received in a dumb fashion, so we are not sure if the values will correctly update. We could correct this by adding a fifo queue on the receiving node (the raspi) and treat the packets one by one, not ignoring some while the last packet is treated.