RTC reference clock detection

[michael2399]

Posted on October 15, 2013 at 14:44

Hello,

we

want to build

a system with

some

STM32F407s

.

For

error

memory

, it is important

that

all controllers

have

the same

time

.

I would like to

use the

RTC and

the

RTC_REFIN

input

to synchronize the

RTCs

.

The RTC

with LSE (32768Hz) runs fine

.

Only the

synchronization does not work

.

On

p

in

PB15

is

a

50Hz

signal.

The

pin

PB15

is

configured as an input

pin

.

REFCKON in RTC_CR

is

also set.

(PREDIV_A=0x7F and PREDIV_S=0xFF, RTC_CALIBR=0x00.)

I checked

this issue

with

Calibration

Clock Out

(1s

) and

a

wake-up

interrupt

(toggle a pin in Interrupt Service Routine)

(

A

timer

I could

easily

sync with my

exteren

clock

).

Does anyone have an

idea

where my

mistake is

? Thanks you. #stm32f4 #refckon #rtc

[Tesla DeLorean]

Posted on October 15, 2013 at 15:54

The

pin

PB15

is

configured as an input

pin

. Would think you'd want an AF configuration, and PinSource'd AF Mux setting.