CYW20719B1 Internal vs External Clock

kmantem · ‎Oct 18, 2021

Hello

We have a custom CYW20719B1 that we are building, but we are looking to use the internal clock. Are there any commands/calls settings we need to make in our code (WICED 6.4) to force the use of internal clock?

We have noticed that when we try to use timers , advertise BLE directly, or wake threads from sleep, we are not able to on the custom board we have developed. These seem to only work if we have a periodic thread running that is in a while loop and waits with KEEP_THREAD_ALIVE set.

AnjanaM_61 · ‎Oct 19, 2021

Hello @kmantem ,

First I would like to tell you that CYW20719B1 is not recommended for new developments. We suggest to use CYW20719B2.

Now for your main query, I think you are not using 32K external clock in your 20719B1 custom board and you are facing issues. Am I correct ?

If then, the issue is in WICED 6.4, by default it tries to enable external LPO and if it is not available then The FW will hang on waiting for the external 32k enable thus causing board dead.

There are ways to enable /disable external 32K crystal in new version 20719B2 (in MTB) but not available explicitly for B1 version.

One suggestion is to try the patches available here: https://community.cypress.com/t5/Knowledge-Base-Articles/Platform-and-New-Patch-Files-For-20719B1-in...

This patches was released so that the 20719B1 modules (which does not have a exteral 32K LPO ) will work. So you can try using this patches in your application and try if it helps. Note : You may have to define the below in platform.h file

#define EXTERNAL_LPO_NOT_PRESENT TRUE

Please let me know if this helps.

Regards,

Anjana

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CYW20719B1 Internal vs External Clock

CYW20719B1 Internal vs External Clock

Re: CYW20719B1 Internal vs External Clock