Stbymode and RTC on STM32F205

[websat13]

Posted on March 20, 2016 at 13:39

hello

i am working on an stm32f205 project. before adding the RTC part , the stbby mode

works fine.

when i added the RTC part   (i tested it and it works fine), but my system dont want to

get in stby mode. the RTC wakeup and alarms are all disabled.

thanks

[Tesla DeLorean]

Posted on March 20, 2016 at 14:46

I have a 205 project where it all seems to work, I wonder what you're doing wrong.

Think about how you can present your problem in a way it might be solved.

[websat13]

Posted on March 20, 2016 at 16:12

hello clive1

thanks for the response.

i have set a push button to enter standby mode, after pressing this button for 1.3s the MCU goes to standby mode. when i push again the button the MCU restarts in run mode.

i added the RTC part. now when i press the push button the MCU executes the standby mode function , but it goes imeediately into Run Mode.

thanks

[Tesla DeLorean]

Posted on March 20, 2016 at 18:35

Perhaps you have neglected to clear some pending state or EXTI?

[websat13]

Posted on March 21, 2016 at 11:08

hello

i have verified all exti pending, i disabled the rtc part and the stby mode works

again.

is there any relation between RTC part and thr standby mode.

thanks

[websat13]

Posted on March 21, 2016 at 12:49

hello

with the debugger here is the RTC_ISR state before activating stbymode (capture.png).

and after executing the function :HAL_PWR_EnterSTANDBYMode(), here is the state of the RTC_ISR regiter (capture1.png).

thanks

________________

Attachments :

Capture.PNG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzTp&d=%2Fa%2F0X0000000bMW%2FZlh3HSXIojj.KAy9.jbZF6.YpLFWtSzYYBhD9B19mt0&asPdf=false

Capture1.PNG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzTj&d=%2Fa%2F0X0000000bMS%2FHOxtor2Mko2_Hs2_fx3mnaIk9L1gFVY4Wm.GoifLmeY&asPdf=false

[Walid FTITI_O]

Posted on March 21, 2016 at 12:59

Hi taleb_bendiab.zakari,

You have to ensure that all wakeup sources' flags are cleared before entering the standby mode, otherwise it will enter and exit instantly by watching one wakeup source activated.

Try always to apply the following sequence before in low power application:

• Disable all used wakeup sources,

• Clear all related wakeup flags,

• Re-enable all used wakeup sources,

• Enter Standby mode

The wakeup flags that you consider in your case are :

PWR_FLAG_WU, PWR_FLAG_SB, RTC_FLAG_WUTF.

If entering and exiting the standby mode several times , check my recommendation in this [DEAD LINK /public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/STM32F437%20exiting%20standby%20incorrectly&currentviews=63]discussion.

The application note http://www.stmicroelectronics.com.cn/st-web-ui/static/active/jp/resource/technical/document/application_note/DM001214pdfcontains an application similar to your case, you may get inspired for your hole application.

-Hannibal-

[websat13]

Posted on March 21, 2016 at 15:21

hello hannibal

thanks a lot for the information. i followed the instructions you give me and the

problem was resolved.

thanks again

[Walid FTITI_O]

Posted on March 23, 2016 at 12:23

Hi taleb_bendiab.zakari,

Nice. Keep up the good work.

-Hannibal-