embedded | I'm teaching myself embedded programming

this code returns me a black screen, what am I doing wrong?

python file:

I'm trying to play a sound just once when a marker is detected with the A-frame and AR.JS libraries.

I'm trying the code lines below but the sound is playing indefinite.

I am trying to implement this code below to catch PDF downloads inside a WKWebView:

How do i delete data from two tables in Android room using a transaction? I cannot have data be deleted from just one table, its both or neither. Both entities have 1 DAO each.

TimerDesign is parent, IntervalDesign is child

I have setup a parent - child class as i will need the 1:M relationship for this class later to get each parent with all its children, at present trying to delete one parent with all its children only deletes from the parent table.

Situation: I am working with a crypto library called embedded disco, I have a demo working on my PC but when porting it over to the MCU I get a hard fault when executing a library procedure. In the faulting code, the library is trying to simply copy the content of one strobe_s struct into another strobe_s. This is done twice: once for s1 and once for s2. For s1, the library simply assigns the dest. struct to the source struct. For s2 however, such an assign gave a hard fault. As the Cortex-M ISA requires aligned memory accesses, I reckoned that replacing the assignment with a memcpy should fix the problem. Nevertheless, simply stepping into memcpy using the debugger results in a hard fault! I.e. I have a breakpoint at the line with the memcpy and when stepping inside the fault handler is called! I have used memcpy to fix misaligned memory accesses in other parts of the code just fine...

MCU: STM32L552ZET6QU

Faulting code:

The code below is my modification of the original library code where the assignment to *s2 was replaced by a memcpy. The original code from the library's github was:

I'd like to have a 2 column reveal.js slide where I can page through the slides in the left-hand column (ColA) while a video plays in the right-hand column (ColB). The slides accompany the video.

I have it laid out on this page but the contents in the iframe/ColA are not large enough to read. I've tried scaling it but it scales the entire containing div, making the two columns overlap, and does not just scale the contents of the iframe.

Another option is to do the slides like normal, where each slide contains a link to the embedded video. My worry there is that every one of the embedded videos will play at once once the page loads because it's a live stream - it seems like that might eat a lot of processing power as my computer tries to play the same embedded live stream in 30 different slides. When moving from Slide1 to Slide2, are embedded videos stopped?

The full git repo for this is here.

I have used Embedded Redis for caching in my springboot application. The redis runs on localhost and default port "6379" on application start up.

Is there a way to get metrics(memory-used, keyspace_hits, keyspace_misses, etc..) for embedded redis, from outside the application, may be command line or any API?

PS: I have used Redisson as client to perform cache operations with redis.

Thanks.

I have a deeplink embedded in my HTML form which is submitted via SendGrid API on nodeJS.

Although the user is able to receive the email, they are unable to click on it.

I am new to embedded C, and I recently watched some videos about volatile qualifier. They all mention about the same things. The scenarios for the use of a volatile qualifier :

1. when reading or writing a variable in ISR (interrupt service routine)
2. RTOS application or multi thread (which is not my case)
3. memory mapped IO (which is also not my case)

My question is that my code does not stuck in the whiletest();function below when my UART receives data and then triggers the void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart) interrupt function