For the Connect Week event put on by Innovate Pasadena, the Hackaday LA group is hosting the “Bring-A-Hack” event where attendees are encouraged to bring projects (in any stage of completion) for show and discussion. Since I’ve been building my LTC-4627JR driver board as a learning project, I wanted to bring it in for show-and-tell.
Now I could just bring the assembled circuit board and pass it around as an inert object, but what fun would that be? I wanted to bring in something that shows it doing something, and provide some way for people to interact with the whole contraption. Looking at my parts on hand, it seemed easiest to rebuild my thermometer test project. I can have a simple Python program run on the Raspberry Pi, reading temperature from the Tux-Lab Si7021 breakout board, and sending it out to my display. That makes 3 circuit boards, plus they’ll need portable power. I will enlist my Amazon purchases: the 3-cell lithium ion battery pack protected by a S-8254A IC, and the MP1584 buck converter to translate the battery pack’s power into Raspberry Pi friendly voltage.
They present a logistics challenge. There are many parts and while it’s fine to just connect them with wires on my work table, it’s too unwieldy to carry on the Gold Line to Pasadena. I’m going to need some kind of enclosure to carry the whole thing.
To Fusion 360 we go! I just needed a simple enclosure so it was pretty fast to draw up. The bottom tray is for power: it holds the battery cells, their protection board, and the buck converter to 5 volt output. The upper tray holds the Raspberry Pi. The lid of the tray holds my custom LED circuit board, and a few clamps holds it all together. The clamps should be easily removable so I could disassemble the box to show people what’s inside.
I had originally intended to mount the Si7021 breakout board as well, but ended up deciding it would be more fun to have it dangling out for people to play with it. Here are the layers without the clamps, so they can be taken apart and show off the insides.
And here’s the “travel configuration”, with clamps holding the pieces together.
This setup worked well. I was able to carry it in my backpack without worrying about tangling up or shorting out wires. Once I arrived, the project was fairly well received and lots of people had fun playing with the thermometer.