topic Re: LPC 4088 RTC in LPC Microcontrollers

LPC 4088 RTC

chaitanyakulkar — Wed, 01 Aug 2018 10:50:05 GMT

I am Using LPC 4088. In which i have using inbuild RTC.The Code Working Properly but after a Removing of VBat. for testing i have Applied VBat Again but that Time RTC Not Working.on Same Code. Even I have reinnetialised RTC After this.So please send me Regarding Changes so that we Can Fixed this Problem.

Re: LPC 4088 RTC

victorjimenez — Thu, 02 Aug 2018 21:24:33 GMT

Hello chaitanya Kulkarni,

I don't know if I understood you correct. When you connect VBAT again the RTC doesn't work at all anymore until you make a reset? Are you using any development board or a custom board?

Regards,

Victor.

Re: LPC 4088 RTC

chaitanyakulkar — Wed, 08 Aug 2018 08:49:18 GMT

Hello Victor,

We are using Custom board and Software Sample code is "LPC Embedded Artist Code".Code is not working After Reset or even after a Reprogram of system still RTC is Not Working.

Re: LPC 4088 RTC

victorjimenez — Thu, 09 Aug 2018 15:14:11 GMT

Hello chaitanya Kulkarni,

Thanks for the reply and for clarifying the information. Are you using the code that is available in the following page: LPCOpen Software for LPC40XX|NXP ?

Since you are using a custom board I will need to take a look into the schematics to rule out hardware problems. A good idea will be to take a look into the schematics of the LPC4088 Experiment Base Board|NXP to use this as a reference to see if everything looks good in your schematics.

Regards,

Victor.

Re: LPC 4088 RTC

chaitanyakulkar — Fri, 10 Aug 2018 09:22:21 GMT

Hello Victor,

We are already Verified our Schematic with reference to LPC4088 Experiment Board (Embedded Artist).We Observed that if system is on and if you remove battery still Time Count Incremented. Before Switched off if we attached battery then still after a resetting system RTC Returns Correct Value. But In This case if System is switched off and you remove the Battery for some time and you still installed a battery before you switched On the System.You switched On System After this Then RTC Value Get Resets (That's OK) but Value is Not getting Incremented(That's the Main Problem )

Re: LPC 4088 RTC

chaitanyakulkar — Sun, 12 Aug 2018 08:47:38 GMT

Hello Victor,

This Issue is Purely based on Software.As RTC Module has Not Getting Supply From VBat and System Supply,RTC SFRs resets Their Value and SFRs get Froze. After Supply Provided to it. RTC will Not Functions Even After Reprogram its.So Problem is to resets all SFR and Re-initialization of RTC.I have Not Getting Code regarding this So Please Reply ASAP Regarding Changes in Code.

Thanking You

Re: LPC 4088 RTC

victorjimenez — Mon, 02 Nov 2020 14:11:41 GMT

Hello chaitanya Kulkarni,

If everything is ok in the hardware then the problem is that you are not initializing the RTC again when you disconnect the system supply and Vbat. I took the the example periph_rtc of the LPCOpen mentioned before (LPCOpen Software for LPC40XX|NXP).

I modified the example to initialize the RTC and set the default hour and date when necessary. To know when I have to initialize the RTC I checked the bit '1' in the CCR register (Clock Control Register) using software. Please see image below, to understand why the bit 1 in the register CCR.

In the example, I added an if condition to check if the RTC need to be initialized then I call the function RTC_INIT and I set the default date and hour. If the RTC is enabled then I do nothing and continue with the program normally to avoid loosing the count of the RTC.

if( (LPC_RTC->CCR & 1) != 1)
{
     Chip_RTC_Init(LPC_RTC);
     /* Set current time for RTC 2:00:00PM, 2012-10-05 */
     Chip_RTC_SetFullTime(LPC_RTC, &FullTime);
}

‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

In the next image you can see the results of running the program.

Hope it helps!

Victor.

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Re: LPC 4088 RTC

alesandro_piazza — Wed, 20 Jan 2021 14:26:49 GMT

hi chaitanyakulkar!

have you solved?

I have the same problem... RTC get stucked and there is no way to reset it again...

problem LPC 4088 RTC stuck but CLKEN = 1 is ok (CCR bit 0)

azzurrodante — Thu, 26 Sep 2024 12:26:26 GMT

I have the same probem :

with battery inserted sometimes i 'have RTC stuck ,

but the register CCR CLOCKENABLE == 1 is ok and data is ok

There is mode to starting RTC withouth remove battery ? i've also insert a code

https://community.nxp.com/t5/LPC-Microcontrollers/LPC-4088-RTC/td-p/807756

that starting Intit rtc only if CCR bit 0 == 0 .

Now for re-starting RTC i need remove battery , power off and power on and Init_Rtc