nrf5340 GPIO not toggling until we do a complete chip power ON OFF

[vinodsdw]

Was trying I2C on GPIO 1.0 & GPIO1.2.

The code worked fine yesterday and today modified few thing and the SDA pin (P1.0) was not toggling at all.

Later tried to make it as normal GPIO Output and tried to toggle it but only SCL pin (P1.2) was toggling but P1.0 was not toggling.

This is not the DK board but an nrf5340 MODULE with complete pinout available for user.

I tried to erase it all using nrfjprog --eraseall and --recover and all was successful but after loading the code only P1.2 was toggling but not P1.0.

I thought the module is not soldered properly or some connection issue.

After troubleshooting for hours, I removed the complete power supply to the module and connected again back.

Then I observed that the pin which was not toggling is toggling and then made it again as I2C and the I2C started working fine without any issue!

So my question is, what is creating such issues? A chip reset or PIN reset should recover what ever issues like this, but why it is not happening in case of NRF5340 ?

This is scary coz we cannot power cycle the IC in a product always if there is no physical power disconnection to the nrf5340.

[Øivind]

Hi,

The issue may be that P1.00, P1.01, P0.11 and P0.10 are by default forwarded to the network core for its UART0. This is set in the node:

gpio_fwd: nrf-gpio-forwarder {
	compatible = "nordic,nrf-gpio-forwarder";
	status = "okay";
	uart {
		gpios = <&gpio1 1 0>, <&gpio1 0 0>, <&gpio0 11 0>, <&gpio0 10 0>;
	};
};

Make sure to either edit this node or use other pins.

[vinodsdw]

I have no other pins free for this purpose.

How can I completely disable those forwarding for using it as gpio controlled by main application cpu?

What is the disadvantage of using these pins are gpio? Is it only for logs ?

[Øivind]

Setting the status of the node to "disabled" instead of "okay" prevents the pins from being forwarded. This will stop logging from the network core, yes.