I had a Timex Data Watch over 30 years ago.

https://en.wikipedia.org/wiki/Timex_Datalink

It'd transfer phone numbers and calendar entries to the watch by blinking the screen of your computer. Kinda a 1 pixel version of this.

(I wonder where that ended up? From memory I threw it in a drawer when I finished the Windows 95 project I'd been working on, and switched to Mac. There was no Mac software to talk to it.)

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atoav 2 hours ago | parent [-]

I have seen digital audio gear that solved firmware transfer like that. You basically go to a website on your phone and it flickers the screen and you hold it in front of a photosensitive bit of the device that needs to be updated for 20 seconds and done.

If your firmware is small enough to fit that model, it isn't a bad variant. Beats downloading a file, transferring it to a USB drive, sticking that in,...

	▲	krautsauer an hour ago \| parent [-]
		That'd be a few 100 bytes at best… what firmware fits into that?