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STM32H7 RTC Alarm OUT

Denys_T
Associate III

Hi,

I'm trying to get an alarm signal on an external contact (PC13). In the program everything works as it should and the interrupt occurs, but nothing changes on the external contact. What did I miss?Screenshot_8.png

 

 

 
 
 
 
 
12 REPLIES 12

An oscilloscope is connected to pin PC13. Perhaps I don’t understand something, I set up an alarm clock in the cube and want to receive an alarm on the PC13 pin. I enabled interrupts and am just waiting for an event on the PC13 pin. And as I already wrote, there is nothing on the oscilloscope, and an interruption occurs. The situation changes if I set an alarm and turn off VDD, then when the alarm goes off, voltage appears on the PC13 pin and remains until I apply VDD again.CR.pngISR.pnggpio_c.png

 

All necessary bits are set

OSEL = 01             ALARM A  

RTC_OUT_RMP = 0       NO REMAP (PC13 OUT )

RTC_ALARM_TYPE =1      PP MODE .  

But whether it should work in active mode, this table does not say anything about this.RTC_FUNCTION.png

 

I also checked the HAL_PWR_EnterSTOPMode and recorded a pulse of about 20us duration

I don't see any reason why wouldn't alarm output work in Active mode of processor.

At this point you may want to contact ST directly, through FAE or web support form.

JW