Not getting cdc_acm prints on mobile USB terminal app

[NM_Z]

Hi Team,

I have nrf52840 DK board and is trying to get the prints from nRF USB port using cdc_acm application. I can see the prints when I connect the DK board with the laptop. But I dont get to see the prints when I connect it to my mobile.

I understand that its unable to draw the current from the mobile. I believe this must be related to some setting in the mobile. If you know, kindly share with me.

PS. I have tried enabling OTG option but that didnt work.

Thanks

NM

[Jørgen Holmefjord]

Hi,

I just tested this on a Google Nexus 7 (2013) tablet, together with Serial USB Terminal application. It works perfectly, without any modifications of settings:

Best regards,
Jørgen

[NM_Z]

Thanks Jorgen! may I know the setting you had to do on the phone for the same?

[Jørgen Holmefjord]

I did not modify any settings on the phone/tablet. I connected the DK's NRF_USB port through a OTG micro-USB adapter, selected the CDC device in the application, and selected connect. I have never used this device with any USB CDC devices before, so it seems to be supported out of the box. Which phone are you testing on? Did you test other phone models? And as awneil asked, does any other USB CDC devices work with this phone?

[NM_Z]

I have a OTG micro USB adapter. Using this I am connecting two mobiles and the mobiles ack with a message that something is connected via USb. If I use the same adapter with the DK board running cdc_acm application, Both mobiles behave differently.

I have Samsung Galaxy Onext Phone, with this LED 1 is solid ON and No activity on LED 2 and LED4

With One Plus Nord, No activity on any LED. This could be as the mobile phone is not giving power to the board. Hence I enabled the OTG mode in the settings. But with this also I don't see any LED blinking.

Any idea what can be done ?

~ NM

[awneil]

again, have you tried any other USB CDC devices work with these phones?

[NM_Z]

No.