dkonigsberg
commented
3 years ago The off-the-shelf caps for the Omron B3F series unfortunately have cutouts on the side. These cutouts prevent the top of the enclosure from being as thin as desired. (It needs to be thin to make up for the fact that the OLED display can't easily be mounted very high above the PCB.)
The only off-the-shelf caps that don't have these cutouts are the square ones from E-Switch, even if they are a bit too tall.
As such, changing tactile switches may not make sense after all. However, custom 3D printed switch caps for the existing switches are still being investigated.
The current prototypes use the E-Switch TL1105SPF160Q tactile switches for the user input buttons. The problem with these switches is that the only off-the-shelf button caps are way too tall (9mm) for the device enclosure design. Their plungers are also 2.8x2.8mm square, which may be limited for custom cap options.
Another switch worth investigating is the Omron B3F-1052. It has the same PCB footprint, but with a smaller 2.4x2.4mm plunger and more off-the-shelf button cap choices. The main choices include square and round caps that are only 5.5mm tall.
The only problem which all of these choices present, is that the off-the-shelf caps may require more of a PCB-to-exterior gap than is desirable to hide the slits on their sides. (There's a limit to how far off the board the display can be mounted, which is a factor here.) So whatever is used, custom button caps may still be necessary.