Cannot tell when a host PC has connected to the nRF52832DK

[RobHel]

Hello. I'm using the nRF52832DK in a test fixture application. 

I need the embedded system to know when either:

- a PC has connected and disconnected to the main USB connector

- a PC host has opened and closed the serial Port of the nRF52832DK

The interface MCU and nRF52832DK are connected via UART utilizing HWFC. However, no amount of adjusting the code on the nRF52832DK can get these RTS/CTS lines to change state. I have my .dts node designed with hw-flow-control set for uart0. 

When I open the terminal using tio, I have tried different flow control settings as well. 

Are there any code samples that utilize HWFC on the nRF52832DK? I would expect these pin values (RTS/CTS) to change based on if a host is connected, yet everytime I probe them, they're 0V. 

Thanks,

Rob

[JONATHAN LL]

Raymond said:

The CTS signal is then "driven"  (Assuming this means driven low) 

Correct, it uses an internal pullup. 

Raymond said:

We aren't seeing that behavior. 

I have not tested this myself atm but I will look in to this. 

Raymond said:

.  I'll reach out to our FAE and sales rep in case that helps you/us get more support on this.  

Yes, always good to push form more than one angle if you need to get things done quick. 


What SDK are you using, NCS verison ?

Regards,
Jonathan

[Raymond]

Hey JONATHAN LL 

Thank you for confirming these things.  We hadn't had a strong enough pull up override the interface MCU's CTS pulldown.   We're now using a stronger pullup and seeing the expected behavior.  

However, just as feedback regarding this product,  it's a real pain for us that the CTS line doesn't return to high-z to indicate when the USB-serial connection is closed.  Without that behavior, there's no way for the application MCU to detect when it has a USB-serial connection established.   

Perhaps this could be an improvement in coming versions of the interface MCU firmware! 

Thanks again

-Ray

[JONATHAN LL]

Thanks for the feedback Ray!