PULL_UP, PULL DOWN and at the centre.

[saharul]

Hi,

How do I know which click works with PULL UP /PULL DOWN. What is the difference between PULL UP,PULL DOWN and the MIDDLE (THE ONE when The swicth is placed at the centre)?

Thank You

[aleksa.jovanovic]

Hi,

The names say it themselves.
The pull-up means that a resistor between the desired line and VCC is connected (usually 4K7) ,
The pull-down means that a resistor between line and GND is connected (again, usually 4K7).
When the switch is in the middle it doesn't do anything.

If some click board needs some pull-up or pull-down it says in the brief manual in the example itself (sometimes I2C lines need a pull-up)

Best regards,
Aleksa

[saharul]

Thanks aleksa.

i can understand PULL UP and PULL DOWN, but not the one in the center. From my understanding it is dangerous to let unconnected to gnd or vcc. it cause floating voltage and cause intermittent.

what application need the switch placed at the centre?

Thanks again

[aleksa.jovanovic]

Hi,

When you connect some device to a pin, if it doesn't say place pull up or pull down, it likely has internal pull up or down or whatever it needs.
So if not specified you should leave it in the middle (unconnected)

Best regards,
Aleksa

[saharul]

Thanks Aleksa