nRF52840 Dev. Kit - User P0.18 instead of RESET

[bonnet]

Hello

  We cannot use the P0.18 pin as standard GPIO on the nRF52840 Dev. Kit.

What are the actions HW / SW to do to use this pin as standard GPIO ?

Should be cut some solder-joints and change SW setup ?

Thanks.

[ovrebekk]

Hi Thierry

The reset functionality and how to disable/enable it is described here. 

Essentially you need to compile your firmware without the CONFIG_GPIO_AS_PINRESET variable defined (the SDK examples include this define by default). 

After removing the define, perform a full chip erase, reflash the code, and you should be good to go. 

Please let me know if you need any more details. 

Best regards
Torbjørn

[bonnet]

Hi Torbjorn,

  Thanks for the answer. On the Dev. kit do we have to cut some jumpers to have this function P0.18 ?

regards.

[ovrebekk]

Hi Thierry

No, you should not need to do any physical modifications to your kit. 

Just be aware that if you press the reset button on your kit it will pull P0.18 low, regardless of how it is configured. As long as you don't press this button the pin should not be affected. 

Best regards
Torbjørn