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Hello,
I'm tyring to program a STM32F4 (with ARM F4) board to generate a sinusoidal PWM, that is a sequence of pulses with variable width that, once filtered by a LPF, gives a sinusoid.
I was told the best way to get it is by generating a sequence of single pulses synchronized to timer by interrupts.
I've tried several solutions but I'm not good at managing interrupts.
Do you have any idea how to achieve this goal? Can you attach a piece of code where it's explained how to do it?
Thanks in advance! ;)
Mara
Thanks for your help!
I'm using the second code, the one with IRQ, but I got 26 errors because a lot of functions and structures you've used are unknown to Keil, like:
TIM_IT_Update TIM_Cmd RCC_AHB1PeriphClockCmd NVIC_InitStructure ... and many more
What library did you use? I can't find none of these functions. Did you program the code for the STM32F401RE?
Just another question ... how can I modify that code if I want to introduce another two phases at 120 and 240 degrees to drive a brushless motor?
"What library did you use? I can't find none of these functions."
I thought Google was available almost world-wide.
I got all the STM32F4 driver libraries I've found on the ST website, but none of them got the functions you've used.
Thsnks for the Code Clive.
It uses the ST Standard Peripheral Library (SPL)
The Red Download button at the bottom www.st.com/.../PF257901
You'd have to make sure the project called out the 401, and configure the PLL correctly in the system_stm32f4xx.c
There are project templates for MDK4, for MDK5 you will probably need to install the Cortex Legacy Pack
The 401C Discovery firmware library may be a shorter jump www.st.com/.../PF259428
Hello Clive,
I'm replacing the functions you've used for the F4 library's functions, so I can better understand what you meant to do.
But there is one thing I can't still figure it out.
Why did you define the "TIM2_IRQHandler(void)" function if you din't even call it in the main part?
Do I have to call it just before the "while(1)" cycle?
Thank you, Mara
It's an Interrupt, it's called by the processor when the TIM2 Update Interrupt asserts. The NVIC/TIM configuration enable this, and the vector table of interrupt handlers are listed in startup_stm32f4xx.s direct execution to the routine.
It will be called outside the flow of regular code, you don't need to explicitly call it. This is how interrupts work. Please refer to Computer Science and Micro-Controller texts if you need foundational understanding.
I'd recommend one of Joseph Yiu's books on the Cortex-Mx series parts, and there are of course ARM's Technical Reference Manuals (TRM) which describe the cores in significant detail.