Thanks Shawn! These videos are awesome, hope to see more STM32 tutorials regardless of the subject! it may be a wormhole, but it'd be interesting to see a generic getting started with TFT display (TFT, SDRAM setup and where to go on the data sheet to find these)
Your tutorial is so clear for a beginner! Thanks so much!!! Please keep it in this style and hope to see more videos from you!!! (only one suggestion, the opening music is quite loud compared to the rest of the video)
Nice! Also, if you don't need any of the timer functionality (like triggering ISRs/callbacks or toggling pins), an easy way to measure times to the nearest millisecond is to use HAL_GetTick(), although you may have to handle overflow cases for very long-running systems (overflow happens after ~49 days and it wraps back around to zero). This function is already setup in HAL_Init(), so no additional setup is necessary. uint32_t start_time = HAL_GetTick(); // do something uint32_t total_time = HAL_GetTick() - start_time; // total time elapsed in milliseconds
Love the use of "sprintf!" Had my encoder (also a subset of timers) sending data, but I'd hit a wall trying to get a comprehensible value to the serial interface. Matching my code to the video confirmed encoder was working as expected without needing to mess with the raw hex that I'd been trying as a first pass.
Thank you so much for these videos. I saw the whole 6 videos. They are really excellent. Can you continue these videos? I will see all of them. And I also like to know about TFT LCDs and more other examples.
Maybe Shawn knows but for everyone else, there's a built terminal in the STM program. Near the bottom right, on that 'console' tab if you lick the icon next to the pc monitor.
I've played with it, and it seems to give me a console out of the IDE or to my PC. I couldn't ever seem to get it to give me a serial connection to my board, so I stuck with using an external program for that. I'd definitely love to know if there's a way to open a serial connection! Maybe I just missed something.
Thanks for video - great series btw; in the interrupt case, I would "if (htim->Instance == TIM16)" which is an included definition in the HAL - this would make things more compatible should the viewers ever want to move that callback out of the main.c (without having to extern htim16 for example)
Are existing other tutorials to make this only in CMSIS? Because learn the HAL with complete other names isn't productive when you had start with the CMSIS.
So do we take value of HCLK or APB1/APB2 Timer clock to prescale upto 1 MHz? Asking because you said if we change the mulplier and prescaler values of HCLK then we will have to consider different values.
first of all thank you for your videos, they are very helpful :) In this video at 9:44 u are saying that it also works if the timer rolls over zero. But if I run this code exactly the way u do it, this does not work... So I had to set the counter to zero after each second to avoid this. Did I make a mistake or how else should it work without this reset?
This may be a dumb question but why don't we just use the timer rollover interrupt handler to write our LED toggle code? It would normally appear above main. What's the purpose of callback functions??
Hi there is there a calculator for STM32 to help me figure out how to setup clocks, prescaler, multipliers output capture for 833.33 microseconds. I’m using the 476RG 106RG nucleo boards thank you.
Hi Shawn Hymel I am working on a simple implementation that checks each character being received using HAL_UART_Recieve_IT and when or is recieved it gets copied to another buffer. I have enabled USART as a global interrupt and wish to know how and where to use the Receive call back function. I am stuck and confused about this from a long time.
Just a quick question on the subject. I am fairly new to Embedded electronics. I am planning to design a midi control surface that incorporates lots of rotary encoders on (as many as possible). I was wondering how I could ascertain how many GPIOs that have "attached" interrupts on them. Would be grateful for any advice here. Otherwise keep up the good work! thanks
Why if i set Period=0, timer doesn't run? I would like to generate an update event at every tick, which would require a Period=1-1, that would make sense... I know I can change the prescalar value to obtain the same update frequency but this "-1" is quite stupid...
It's interesting that Timer's 'auto-reload preload' can be set to Disable, and you don't need to manually reload the counter in code! Regarding using a Timer for polling elapsed time, how does it differ from using HAL_GetTick(), i.e. no Timer? If using the Timer to trigger an ADC reading.. it seems the number of samples captured for an input sine-wave (single cycle), is dependent on the number of channels in the Scan. In other words, if NbrOfConversion=1, then the ADC will capture samples equal to the Timer rate.. but if NbrOfConversion>1, then only one channel gets converted per trigger event, the next channel in the scan list is captured only on the next trigger event? Speaking of Output-Compare, what does the "Pulse" field do? It seems it's necessary to be set to 1? For example, if Output-Compare is set to to Toggle on Match, with Trigger TRGO Event = Update , and if the Timer Clock is 120Mhz (Prescaler = 60-1, Preload 62-1), then the Ouput-Compare GPIO should toggle at 32khz.. so assuming one channel in the Scan list, how often will the ADC sample the channel?
I wasn’t aware of all the clock functions that were imbedded in this astm32. This will take awhile to grasp, and to find new applications. Just thinking about it hurts. 😔
It's a lot! That's why I had to only focus on a few functions at once with the video. I still don't know how to use all of the features (or even what some of them mean!). One step at a time..learning how to measure time (such as milliseconds) is a good start :)
Callbacks are functions that you define in your code that are called from somewhere else (usually in a library or back-end). Often, a pointer to the function can be passed as an argument to that back-end code so that you can name the callback function whatever you want. It allows you to define a function and let something else call it, even if you don't know when that will be (they form the basis for event-driven programming). Here is a good example of how a callback might work in C: stackoverflow.com/questions/142789/what-is-a-callback-in-c-and-how-are-they-implemented
9:48 if (__HAL_TIM_GET_COUNTER(&htim16) - timer_val >= 10000)... isn't correct (missing cast). You need to do something like this: uint16_t tim16 = __HAL_TIM_GET_COUNTER(&htim16); if ((uint16_t)(tim16 - timer_val) >= 10000){ // ... do something timer_val = tim16; }
At 10:00 this shouldn't work after a while right? If timer_val is 65,000, then __HAL_TIM_GET_COUNTER(&htim16) runs, this will give a value like 400, since it rolled over 400-65,000 >= 10,000 is false Unless maybe you do some casting, but then it will almost always be true You have to reset the timer, or have some extra logic
more videos please ........................................!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!........................................!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
