So I've been at this for several days now with no luck, and it's time to ask for help! I promise I've searched the forum and read everything I can.

So I can get my I2C 20x04 LCD display running fine with the LiquidCrystalIO > HelloI2C example. So my hardware is fine.

I'm starting with the most straightforward simple menu I can create, to get it working first, and then go from there. The example I created was literally a single analogue item in Tc Menu Designer 1.7.5 for MacOS. This compiles perfectly, and uploads to my device, but nothing is appearing on the screen. From what I have read, I don't need to call anything and by default the menu should appear but this is not happening. It must be something simple, but I'm baffled. Where do I start?

Edit to add: I've got an encoder set up on pins 2 and 3, with the switch on pin4. I'm using an Arduino Mega 2560. I've followed this exactly: https://www.thecoderscorner.com/products/arduino-libraries/tc-menu/tcmenu-overview-quick-start/ and I'm getting nothing at all.

Thanks for reporting with all the details, I'll try and build the project later today using Arduino and feedback here.

In the designer code generator, under display settings, there's an option for the "LCD Pin Layout". I think you've picked the opposite one to which is the default in the HelloI2C sketch. Could you try the other option please and let me know if it works.

It will have options for RS_RW_EN and EN_RW_RS. Basically, can you try the other option?

Many thanks.

A bit more background.

Basically, the I2C backpacks are not standard, some use RS-RW-EN and some use EN-RW-RS. We don't try to guess them, instead, we just rely on you trying both options.

Bravo! Solved. Many, many thanks! Was indeed the weird I2C.