I’m back! Finalized the second PCB for the keys

Well, yeah, I’m here again. I’m back, it’s been a while since I was away, right? I waited for things to settle down here so I could continue with the project.

Yeah, and I finalized the idea of making a board on the second PCB there, where the buttons will be, you know, the clicks to use the calculator keys . And this here was kind of leftover code organization I was doing in the repository . I ended up not remembering everything from the project, but now I’m here again. So I’ll finish this up. It was pretty simple, I didn’t record it.

But basically, I made a 7x7 matrix of switches , the buttons. Along with that, there’s the FPC connector to actually connect the board to the ribbon, to the rest of the MCP expander. I’m going to tidy it up a bit.

The board also ended up being quite small 84x78 basically just to fit there, it would provide support and, you know, fit the switches at the distances that had already been predetermined in the case, right in the middle of the product’s housing.

And then, along with that, the schematic is also simple, I just put an FPC connector, that’s all that’s really needed, and the buttons, the switches. Really simple.

I think it’s interesting to mention (diodes & debounce):

I was also going to use, you know, I was looking, people were saying, it’s good to use diodes, but just to kind of reduce debounce, fix certain issues, but it wouldn’t be that necessary, since the contacts closing would almost never happen like, I don’t know, three clicks at once, one next to the other.

So that doesn’t really cause a problem where the ESP wouldn’t know exactly which key is being pressed and what it should do with the signal it’s receiving. And depending on how you study it and see how to handle it in the firmware, it actually wouldn’t even be that necessary to put these diodes on each of these buttons for that.