High Z Pins?

[MoonGoon]

Is it possible to make a pin go high imedance?

Im attempting to Charlieplex five 7-segment displays. I can successfully get a current draw into a Low pin when wanting. But on pins i dont want to draw current, i cant make them High because the segment will light up.

Does anyone know of a technique to stop a pin from drawing current without making it go High?

Is there a command for a PICAXE to go High Z .. or is it disabled for PICAXE?

Any thoughts would be appreciated.

 

[Dippy]

If you make a pin an 'input' it is pretty high impedance - check out the Microchip Data SHEET.

Command HIGH for an output pin essentially conencts the pin to V+ and , conversely, LOW connects it to Gnd/0V. (For pedants: yeah I know...)

 

[hippy]

As Dippy says, it's the INPUT command you need or LET DIRS / LET DIRSC. Not all PICAXE's support those and not all pins can be made inputs. The 18X for example has fixed outputs but there is a technique to turn those outputs into inputs.

A forum search should turn up information on charlieplexing and how well it has worked ( or not ). The PICAXE is a fairly slow executing device so charlieplexing isn't always as successful as hoped for when trying to control multiple LED's or 7-segment displays.