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msp430 RTC display problem

BINU K
Intellectual 935 points
Other Parts Discussed in Thread: MSP430FR5739

Hai all

  Iam trying to display the RTC value of msp430fr5739 on LCD and UART 

Iam using CCS v6. I test RTC and uart  but problem is that  when reading second and minute  the value display as ASCII character. How to convert it to decimel?

Can I directly access RTCSEC reg anywhere?

When I display it on lcd only one decimel place is print example as when we want to print 23 , it print only 2 but the RTC incrimented  correctly and minut interrupt works properly.

The main configuration are below 

 RTCCTL01 |= RTCTEVIE + RTCRDYIE +RTCHOLD+RTCBCD;   //register config

//ISR

#pragma vector=RTC_VECTOR
__interrupt void RTC_ISR(void)
{
switch(__even_in_range(RTCIV,16))
{
case RTC_NONE: // No interrupts
break;
case RTC_RTCRDYIFG: // RTCRDYIFG
P1OUT ^= 0x01; // Toggles P1.0 every second
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF =RTCMIN;
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF =RTCSEC;

break;
case RTC_RTCTEVIFG: // RTCEVIFG
__no_operation(); // Interrupts every minute
break;
case RTC_RTCAIFG: // RTCAIFG
break;
case RTC_RT0PSIFG: // RT0PSIFG
break;
case RTC_RT1PSIFG: // RT1PSIFG
break;
case 12: break; // Reserved
case 14: break; // Reserved
case 16: break; // Reserved
default: break;
}
}

  • 0
    Guru 25210 points

    BINU K said:
    Can I directly access RTCSEC reg anywhere?

    Yes.

    BINU K said:
    When I display it on lcd only one decimel place is print example as when we want to print 23 , it print only 2 but the RTC incrimented  correctly and minut interrupt works properly.

    You configure the RTC for BCD mode on the registers. Therefore the RTCSEC register is encoded as a packed BCD. To properly display the value on a terminal, you need to convert the value into two ASCII characters. Example:

    char rtcsecbcd, char1, char2;

rtcsecbcd = RTCSEC; // Get the value atomically before parsing
char1 = ((rtcsecbcd>> 4) & 0x07) + 0x30; // Tens digit of seconds
char2 = (rtcsecbcd & 0x0F) +0x30; // Ones digit of seconds

    Also, polling on the UART flags to transmit multiple characters inside an ISR is bad practice. No other ISR's can happen during the time it takes to transmit all those characters. In a proper system, you should have a UART driver with a queue, and inside your RTC ISR, you just add the characters to the UART driver queue, and the UART driver sends the characters on an interrupt-based process.

  • 0 in reply to Brian Boorman
    Intellectual 935 points

    thank you Brian , It works

    It working in UART and Iam trying to check in LCD

  • 0 in reply to Brian Boorman
    Intellectual 935 points

    hai all,

        I get hour,minute and second correctly, but problem is that it is in char , I want to take a single intiger value

    these are working code for ones and tens position

    rtcsecbcd = RTCSEC; // Get the value atomically before parsing
    sec2 = (rtcsecbcd & 0x0F) +0x30; // Ones digit of seconds
    sec1 = ((rtcsecbcd>> 4) & 0x07) + 0x30; // Tens digit of seconds

    rtcminbcd = RTCMIN; // Get the value atomically before parsing
    min1 = ((rtcminbcd>> 4) & 0x07) + 0x30; // Tens digit 
    min2 = (rtcminbcd & 0x0F) +0x30; // Ones digit
    rtchourbcd = RTCHOUR; // 
    hour2 = (rtchourbcd & 0x0F) +0x30; // Ones digit
    hour1 = ((rtchourbcd &0x30)>>4)+0x30; // Tens digit

    and I try like this

    second=sec1*10+sec2

    but not working , can suggest a method?

    I want to write a value from keypad and serialy received data and also read

    please help

     

  • 0 in reply to BINU K
    Guru 227245 points

    The conversion used for sec2 and sec1 converts the BCD value form the RTC into two human-readable digits (ASCII code).
    If you want a numerical value for the seconds, you don’t have to add the 0x30 (which is the ASCII code offset of the ‘0’ letter).
    Or you configure the RTC to not use BCD mode. Then the content of the RTCSEC register is already the numerical value (0..59).
    Same for all other RTC registers.

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