What I want module makers to do

People who make modules tend to get it working and start shipping before they think things through. Not everyone can have a focus committee. Therefore I propose that we do it for them.

I need the ability to hard mount a module. no less than three screw holes, preferably 3.5 mm for both 3 mm & 4-40 screws

I would prefer that they came with the header not attached, and the SMA connector unattached, because if I need straight up connectors I get 90s on the wrong side of the board.

5 hole SMA connections give you many mounting options. 3 tabs give you one. There should be a way to disconnect the built in antenna if you need an external antenna

if the wizard who designed the LCD I2C backpack had shifted the 4 pin connector 2 hole locations, .2", to the inside of the module you could use 4-40 standoffs on all 4 corners

a one channel optocoupler or level converter would be nice. a 12 VDC to 3.3 level signal converter would be nice.

putting a battery the size of an aspirin on a module is silly. put a JST connector on it, or a CR2032

If a module takes 5 V power and 3.3V signal should it not have a zener diode on that 3.3V input?

if you could get the attention of those guys for 1 minute, what would you suggest?

added: I mount NANOs on perfboard ans I add a pair of jumpers for 0 & 1. I can use Serial and disconnect 0 & 1 for uploading.

I2C device makers should put address change pins on every board, regardless of function.

Yes! I despise modules without mounting holes. I don't mess with glue or tape in my finished projects and I'm certainly not going to leave the module hanging loose from its wires inside the enclosure so I end up mounting those modules without holes by sandwiching the edge of the PCB between two washers mounted to a standoff with a screw. That is really a pain to do and it can be difficult to even find areas of the PCB that are free from components to do this with.

I'm actually surprised I haven't found some sort of plastic PCB mounting brackets for this purpose. I have spent some time looking for them.

The only exception to the mounting hole requirement is if the module is in a DIP format, with the pins on a standard grid so that I can mount it by headers or soldering to a stripboard.

At least offer the option of without headers. For beginners, pre-soldered headers are nice because they might not own a soldering iron but it is a pain when you have to desolder a header from something to replace it with the one you need.

Put the darn PTH on a 0.1" grid. I bought every common cheap step down and boost converter module on eBay and only a few of them ended up being on-grid. To use the off-grid ones I either need to mount the module separately (which is a lot of extra work even when there are mounting holes and results in more wires cluttering things up), or else make a custom PCB with custom footprint for that module's pin spacing. What a joke!

sandwiching the edge of the PCB between two washers

...with nylon washers and nylon screws, no doubt.

I tend to mount small things with many wires in pill bottles. my supply of film cans dried up. this is a good excuse to buy a 3d plotter

3D printing your own cases does away with much of the module mounting issues. You can get really creative if you can design it yourself. At least that's what I do. For example the Teensy 3.2 is like mounting a tiny porcupine. Nothing but connections everywhere. But it such a nice processor, I came up with a small click-in mount I can add to my projects just to hold one.

-jim lee