Hardware Limitations for Using P0.27 as UART RX on DWM3001CDK

[oussema ben khedher]

Hi,

I'm working with the DWM3001CDK (nRF52833 + DW3110) and currently using SPI to interface with the DW3110 for UWB communication.

I'm trying to use a second UART to communicate with another external MCU, and I wanted to repurpose P0.27 as UART RX. However, it doesn't seem to work properly, while P0.07 works fine.

I found that P0.27 is connected to the DW3110's IRQ line, which is used for UWB interrupt signaling. I understand this might conflict with UART usage, but I wanted to ask:

My Questions:

1. Is there a hardware limitation that prevents using P0.27 as UART RX?

2. Is the IRQ pin of the DW3110 actively driving P0.27, even if I don't explicitly enable IRQ in software?

3. Can you confirm if P0.27 is strictly reserved and should not be repurposed in this context?

[Priyanka]

Hi,

Is there a hardware limitation that prevents using P0.27 as UART RX?

Since you mention that P0.27 is connected to the DW3110's IRQ line, then it's not recommended to use this for other purposes that can interfere the performance. Theoretically the P0.27 is recommended to use for low - frequency operations due to the proximity to the radio.

Is the IRQ pin of the DW3110 actively driving P0.27, even if I don't explicitly enable IRQ in software?

Maybe yes, but I am not the expert to talk about this. I would suggest you to contact Qorvo's Techsupport for the matter.

Can you confirm if P0.27 is strictly reserved and should not be repurposed in this context?

As mentioned earlier, the nRF52833 allows flexible pin assignment, but P0.27 is recommended for low-frequency use and, more importantly, is already connected to the DW3110 IRQ on your DK, so I wouldn't recommend using that pin.

Regards,

Priyanka