Is there a way to configure an IO port as high-impedance?

[leo b.]

Hi,

I've tried to search the documents and the forum for an answer to my question, but didn't have much luck.

We have a custom board that uses a STM32 micro and nRF51822 at the same time. When the board was being designed, we didn't know if we were going to use SPI or I2C for communication between the two micros. So, the SPI and I2C lines were added between the two micros. During coding, we eventually went with using the SPI. However, with the I2C lines still present on the hardware, it is affecting the I2C communication between the STM32 micro and the other sensors.

Is there a way to configure the GPIO ports on the nRF51822 as high-impedance? That way it wouldn't affect the other devices using the I2C lines.

Any help is much appreciated.

Thanks,

Leo

[Moloch]

Set the GPIO pin to be an input with no pull resistor if you want it to have a high impedance.

Switch it back to an output when you're ready to use the pin.

Use the #defined macros in nrf51_bitfields.h and nrf51.h or the examples in the Nordic SDK to see how this is done.

[leo b.]

Thank you for the reply. I used to work on the older 4-bit microcontrollers and their IO ports were configurable to be high impedance and were described in detail in their data sheets. But for the nRF51822, I didn't find any mention that described a state where the IO ports are configurable as high-impedance.