[sdiy] get 5V from 12V - DC-DC converter or 7805?

[Ingo Debus]

> Am 28.12.2020 um 13:14 schrieb Tom Wiltshire <tom at electricdruid.net>:
> 
> That’s a good idea since that’ll likely be the heaviest current draw of anything on the module.

Florian wrote the thing should be powered from either a 12 V rail or a 9 V wall wart. Don’t know if the variations in backlight brightness are acceptable or not.
If not, a current source built with a LM317 or something like the LT3092 could be used.

Extra low power dissipation could be achieved with a switch mode power supply with regulated output current (rather than output voltage).

Ingo