How to properly tie the shutdown pin of the AD8232

[MildInductor]

Hello, I am looking at the DF Robot schematic for their AD8232 board. I see that they have tied the shutdown pin to 3V3 through a 10K resistor. I am wondering why they have used a pull-up resistor? Could the shutdown pin just be connected to 3V3 directly? The datasheet for the AD8232 makes no mention of whether a pull-up should be used or not.

[ArdWar]

Could the shutdown pin just be connected to 3V3 directly?

Yes

I am wondering why they have used a pull-up resistor?

There are several reason pulling up/down with resistor instead of direct connection are preferred (technical need when there's voltage mismatch aside). Most of the time it is so that the signal can be overridden with other logic signal if needed, the pull up/down resistor here serve to establish a "default" state when there are no external signal present. Other common reason is putting both up and down resistor footprint and only populating one as a means of hardware configuration.

Although sometimes it's just habit/superstition. Some people aren't comfortable connecting signals directly to low impedance supply nodes.

[MildInductor]

I see, that clears things up. So by the sound of it the resistor is unnecessary, but not harmful.