ble_app_hrs_freertos 2

[samsam]

By some strange reason the thread with my previous question cant accept any replies (and missing the toolbar that appears on the other threads: "Reply Like More"), so will continue here:

Thanks for the answers:

Regarding p.2 – I already mentioned “And I tried almost all combination for the type of the buffer or casting it in the NRF_LOG_INFO statement”, so here is attached and exactly the variant with the char buffer – same problem – but only happens when use FreeRTOS. In the examples without FreeRTOS I tried so far, the snippet works perfect and with char and with uint8_t

 NRF_LOG_INFO("HRS FreeRTOS example started. 3");

 char bc_buf2[] = {'9','7','5','3','\0'};

 NRF_LOG_INFO("\n Received BC2: %s \n", bc_buf2); //WTF doesnt print %s

 uint32_t uint2 = 223377;

 NRF_LOG_INFO("\n Received ui32: %d \n", uint2); // %d  is Ok

 

Tera Term output:

<info> app: HRS FreeRTOS example started. 3

 <info> app:

 Received BC2: Ào

 <info> app:

 Received ui32: 223377

 <info> app: Fast advertising.

 

JLink RTT Viewer output:

00> <info> app: HRS FreeRTOS example started. 3

00>

00> <info> app:

00>  Received BC2: Ào

00>

00> <info> app:

00>  Received ui32: 223377

00>

00> <info> app: Fast advertising.

00>

ble_app_hrs_freertos2.zip

Regarding p.1 – is there anywhere in the documentation written the explanation you posted as I guess there will be and other differences, but the only place I found in the docs regarding FreeRTOS implementation is quite scanty

 https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Ffreertos.html

[Susheel Nuguru]

what happens if you define your buffer like below?

char bc_buf2[] = "9753";

[samsam]

Same problem. Actually almost same because the junk printed differs. Also - as I already mentioned - this problem happens only when using FreeRTOS, with the other examples my tests with the same snippet dont exhibit this problem:

This:

NRF_LOG_INFO("HRS FreeRTOS example started. 3");
char bc_buf2[] = {'9','7','5','3','\0'};
NRF_LOG_INFO("\n Received BC2: %s \n", bc_buf2); //WTF doesnt print %s
char bc_buf3[] = "9753";
NRF_LOG_INFO("\n buf3: %s \n", bc_buf3); //WTF doesnt print %s
uint32_t uint2 = 223377;
NRF_LOG_INFO("\n Received ui32: %d \n", uint2); // %d is Ok

Produces this:

<info> app: HRS FreeRTOS example started. 3

<info> app:
Received BC2: Ào

<info> app:
buf3: 0ï

<info> app:
Received ui32: 223377

<info> app: Fast advertising.

Attached is the whole modified ble_app_hrs_freertos example:

ble_app_hrs_freertos3.zip

[Susheel Nuguru]

Just looked into your code now and understood that you are declaring bc_buf2 in main function but trying to access it in different tasks. This might work on baremetal flow but is risky in an RTOS context. The static memory space of bc_buf2 is not guaranteed to be preserved when the logger thread accesses this pointer when it gets time to process the dereferred logs.

I did not run your code yet, but i think making the declarations static would guarantee that this pointer bc_buf2 has a static memory address.

Could you please give it a try.

[samsam]

This is not the right spot to reply, but again - your last posting does not allow me to Reply, so don't have other choice than reply here:

- yes with static work both ways :)  The only problem I see here: if have to log a lot of static strings  - that is a lot of unnecessary memory overload - shouldn't be a better way with dynamic allocation that will be available to the task that will actually process it???

Also - could you please answer 

samsam said:

Regarding p.1 – is there anywhere in the documentation written the explanation you posted as I guess there will be and other differences, but the only place I found in the docs regarding FreeRTOS implementation is quite scanty

 https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Ffreertos.htm

I don't wan to bother you or your colleagues for every little obstacles if I can find it easy and myself?

Thanks

[Susheel Nuguru]

samsam said:

yes with static work both ways :)  The only problem I see here: if have to log a lot of static strings  - that is a lot of unnecessary memory overload

 It does not seem like you understand the memory allocation/freeing of stack memory. The define of static here is to tell the compiler that this space will not be living in dynamical stack frame but instead a static space that is not freed. When you call a NRF_LOG_INFO, the log is not processed immediately, but it is processed when your logger_thread runs in idle time. At that time if your buffers bc_buf2 and bc_buf3 might have already been freed and allocated for something else in stack frame context. So the static keyword is absolutely necessary. Else you need to declare them in the global context and not inside the main function