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Guidoted · 2024-07-08

I have a timer (TIM10) with a period of 500 us, running without interrupt or any other function.Then I have a rising+falling signal interrupt on PB0 (EXTI0) driven with a 31.25 kHz square wave.In EXTI0 I read the CNT value into a variable New, evalua...

Guidoted · 2024-03-19

I developed a 62.5kbit synchronous self-clocked (similar to SDLC) communication firmware for STM32F412, to be interfaced with an old device via RS485.It works in "bitbanging" using a 16us interrupt timer (TIM11) to sample the bits and EXTI0 (PB0) int...

Guidoted · 2021-12-17

On a STM32F412 I need to have an I2C slave that may be required to transmit or receive data without knowing it first.The problem is that we have two separate functions:HAL_I2C_Slave_Receive_IT to receive data from the master, but the driver will hang...

Guidoted · 2020-03-11

I'm developing a SPI bootloader, using the integrated function of STM32F412, and I found two strange behaviours:I must issue two times the reset of MCU with Boot0 high, because after the first reset the MCU seems to be in bootloader mode but doesn't ...

Guidoted · 2020-03-03

I'm simulating some issues on my STM32F412 DMA SPI SLAVE because I need to avoid any unrecoverable situation.If for any reason the TX is not empty (TXE is 0), I'm not able to reset it (set to 1) even reinitializing the peripheral.Probably, something ...

Guidoted · 2024-07-09

Many thanks JW and Barry,now I understood what happens and clearly my problem is that EXTIO0 interrupt contnues to run with my square wave input on PB0 and continues to change the variable values.I will do more test to understand it better.Thanks aga...

Guidoted · 2024-07-09

Thanks JW, but I don't watch the CNT values, I watch the values of variables timerDiff16, timerNew16 and timerOld16.Are you saying that debugger is changing the variable values?

Guidoted · 2024-07-08

Please read "the interrupt happens every about 16 microseconds"

Guidoted · 2024-07-08

So, this is the code that currently gives me the same wrong results with both 16 and 32 bit variables. void EXTI0_IRQHandler(void){static uint16_t timerNew16, timerOld16, timerDiff16;static uint32_t timerNew32, timerOld32, timerDiff32; DBG2_GPIO_Port...

Guidoted · 2024-07-08

Thanks JW and Gdm, I will investigate further. P.S. newTimwer = TIM11->CNT; instead of newTimwer = TIM10->CNT; was a mistypo ;)

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Strange values when reading timer CNT

EXTI0 double interrupt on one edge

STM32F412 I2C slave that may be required to transmit or receive (non blocking with interrupt) without knowing it first?

Strange behaviours of SPI bootloader on STM32F412

How to reset TXE flag on SPI slave?

Re: Strange values when reading timer CNT

Re: Strange values when reading timer CNT

Re: Strange values when reading timer CNT

Re: Strange values when reading timer CNT

Re: Strange values when reading timer CNT