On Mon, 22 Aug 2011 16:16:38 +0100, Dave Plowman (News) wrote:

Bought a rather nice small LED voltmeter off Ebay for not a lot. It's a
3 digit type. For the old Rover which didn't have any battery indication
- intend fitting it in the middle of the rev-counter face. However, it's
a bit bright for night time. Any clues about dimming it? Can't get a
data sheet for it - came from the far east. The PCB has a single
processor and two regulators - one 5 volt and one 3.3v. I'd guess the
latter is for the display. But being surface mount, rather difficult to
suss out the schematic.

How are the LED segments driven? 3-digit is 21 segments (ignoring DP) -
are each of those controlled by a single pin on the IC?