CC1352P: How can use external 32kHz crystal

I suppose you should select LF_XOSC in your sysconf.

Hi YiKai,

I have made the required changes from sysconfig.

But still my BLE device is working without crystal.

Regrads,

Vijendra

Can you try to use LF RCOSC instead of LF_XOSC? It seems that sysconf makes those two settings reversed.

Hi YiKai Chen,

How can I confirm that it is working on external crystal?

Regards,

Vijendra

Removing external crustal and if it doesn't work, it mean your application runs on external crystal.

It is working in both conditions.If I removed external crystal then also scanning and Advertising,UART etc are working.

Can you try it with simple_peripheral example which enable POWER_SAVING?

I am using Host test application without power saving mode.

So, can you try simple_peripheral example?

Same behaviour observed with simple peripheral.

Means module which do not have external crystal also advertising.

The examples in the SDK uses external 32 kHz xtal by default.

I believe it's easier to see the difference with external/ internal oscillator using the empty example from the SDK. 

Hi TER,

Agreed,But these example also working with Crystal less modules.

Regards,

Vijendra

HI TER,

Is there any Fallback to internal crystal if external is not there?

Regards,

Vijendra

Internal RC would be less accurate and consumes a little more power than external crystal.

Thanks for reply.

Still I am not able to confirm that my module is working on external crystal or internal.

Bcz with external crystal configurations Firmware is working with crystal less modules also.

So I want to know that Is there any fallback to internal crystal?

Regards,

Vijendra

What is the background for the question?

I have to check to start-up code a bit after Easter but I believe that if an external xtal is not present the chip will never go to sleep (if you have set the chip to use external xtal).

Have you checked the current profile in the different cases?

I am assuming that if an external xtal is not present then the chip will not work(if firmware having external xtal config).Is my assumption right?

I was checking broadcasting and scanning with external crystal using HCI commands and that was working on crystal less modules.

I will check the current profile 

Regards,

Vijendra

What I typically see with customer designs that don't have the 32 kHz osc mounted but haven't changed the settings to use the internal osc is that the chip works but it's not able to go to standby since the LF clock is missing.

I believe it's a check in the power driver for this, you can dig into the startup sequence code to check how the clock selection code is done.

Vijendra Goyal1 you can try to test simple_peripheral example and use power analyzer to check if it can enter sleeping mode to verify if it uses external crystal.