Sometimes having sensor data piped over RF to your database or to your console is not enough. Sometimes you want a big display displaying your numbers you could just throw a look at. Sometimes you want to package your sensor and a display to a person at industrial facility so they could quickly measure something without involving connectivity and computer.

Thus 2 years ago I started on a journey to design myself a display like that. The device had to be battery operated - wall plug devices are a thing of the past, so e-paper was an easy choice for the display technology - low power, high contrast, relatively high resolution.

I am not very good at mechanical design, so I wanted to piggyback on something that's available, thus I stumbled on electronic label enclosure kit available from GooDisplay

This case has features allowing for two 2450 coin cell batteries, I hoped to sneak in whatever sensor wires I need via strategically drilled hole.

So I have designed a PCB specifically for this case.

On the top left you can see e-paper display power related components. Top right is a boost converted for voltage regulation and bottom right is an ATSAMD21G18A micro-controller. The choice for the micro-controller was mainly steered by availability and good software support available from Adafruit for their feather boards - I wanted to take advantage of that.

After finishing the design I put it on a shelf as pandemic was in full swing, so I had another things to worry about, but after some time I came back and had another look - all this effort for just adding a display? Maybe I could beef it up somehow with additional functionality?