How to configure GPIO output to float?

RE: How to configure GPIO output to float?

JohnBrown — Tue, 15 Sep 2015 07:08:15 GMT

If you're using the nRF51822, then the I/O pins are very configurable. You can set an individual pin as S0D1, which is shorthand for "Standard 0, Disconnect 1". That should be exactly what you are looking for.

RE: How to configure GPIO output to float?

Stefan Birnir Sverrisson — Mon, 14 Sep 2015 09:59:43 GMT

Hi Jerod

A GPIO pin is by default, i.e. when you have not configured it, in high impedance state. That means that the voltage on the pin will be floating if no external circuit pulls the voltage up or down. If you have configured the pin already you can put the pin into its original high impedance state by calling nrf_gpio_cfg_default in nrf_gpio.h

RE: How to configure GPIO output to float?

Alex — Mon, 14 Sep 2015 09:58:38 GMT

Odd person is correct, configuring IO as input makes it "floating". But I would also add that your additional hardware most likely has internal pull-up that's why you can have EN pin left floating to perform powe on. Check it in the device datasheet and if it is true then you probably don't need to configure nRF IO as input, it will be fine to set it high to enable hardware. Unless EN pin has three input states such as high, low and floating but it is usually for some kind of mode rather than simple on/off.