Kenji Arai / Mbed OS Nucleo_RTC_battery_bkup_pwr_off_okay

In the past, you need modify rtc_api.c in mbed-dev source code. From this revision, you can just use RTC function all of conditions (Normal, Reset, Stand-by, Power OFF).

Note

From now on, you do NOT need any modification for mbed-dev library because STM team updates rtc_api.c source code and support RTC function under reset & standby condition includes power off condition (You need additional VBAT back-up hardware).

Please refer following NOTE information.
/users/kenjiArai/notebook/nucleo-series-rtc-control-under-power-onoff-and-re/

main.cpp

Committer:
kenjiArai
Date:
2015-02-07
Revision:
0:0751c92c0f71
Child:
1:7a48c475bbd2

File content as of revision 0:0751c92c0f71:

/*
 * mbed Application program
 *      RTC (inside STM32x CPU) test program
 *
 * Copyright (c) 2015 Kenji Arai / JH1PJL
 *  http://www.page.sannet.ne.jp/kenjia/index.html
 *  http://mbed.org/users/kenjiArai/
 *      Created: January   17th, 2015
 *      Revised: Feburary   7th, 2015
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

//  Include ---------------------------------------------------------------------------------------
#include "mbed.h"
#include "TextLCD.h"
#include "SetRTC.h"

//  Definition ------------------------------------------------------------------------------------
#define SHOW_KEY_PROMPT     30

#define USE_LCD

//  Object ----------------------------------------------------------------------------------------
DigitalIn userSW(USER_BUTTON);
DigitalOut myled(LED1);         // Indicate the sampling period
Serial pc(USBTX, USBRX);
#if defined(USE_LCD)
I2C i2c(D14,D15);               // SDA, SCL
TextLCD_I2C_N lcd(&i2c, 0x7c, TextLCD::LCD8x2);  // LCD(Akizuki AQM0802A)
#endif

//  RAM -------------------------------------------------------------------------------------------

//  ROM / Constant data ---------------------------------------------------------------------------

//  Function prototypes ---------------------------------------------------------------------------

//-------------------------------------------------------------------------------------------------
//  Control Program
//-------------------------------------------------------------------------------------------------
int main()
{
    char buf[42];               // data buffer for text
    time_t seconds;
    uint8_t counter = SHOW_KEY_PROMPT;

#if defined(USE_LCD)
    // lcd
    lcd.locate(0, 0);    // 1st line top
    //          12345678
    lcd.printf("  RTC   ");
    lcd.locate(0, 1);    // 2nd line top
    //        12345678
    lcd.puts(" JH1PJL ");
    lcd.setContrast(0x14);
#endif
    pc.printf("\r\n\r\nTest Nucleo RTC Function\r\n");
    // waiting for Initial screen
    myled = 1;
    wait(1.0);
    myled = !myled;
    wait(1.0);
    myled = !myled;
    if (SetRTC() == OK) {
        pc.printf("External Xtal for RTC\r\n");
    } else {
        pc.printf("Internal Xtal for RTC\r\n");
    }
    show_RTC_reg(); // only for debug purpose
    while(1) {
        myled = !myled;
        seconds = time(NULL);
        strftime(buf, 40, " %B %d,'%y, %H:%M:%S\r\n", localtime(&seconds));
        pc.printf("[Time] %s", buf);
#if defined(USE_LCD)
        lcd.locate(0, 0);    // 1st line top
        strftime(buf, 40, "%b%d'%y", localtime(&seconds));
        lcd.printf(buf);
        lcd.locate(0, 1);    // 2nd line top
        strftime(buf, 10, "%H:%M:%S", localtime(&seconds));
        lcd.printf(buf);
#endif
        if (counter){
            --counter;
            //      012345678901234567890123456789012345678901234567890123456789012
            pc.printf("Is time correct? If okay, nothing. If not, please hit any key.\r");
            wait(1.0);
            if (pc.readable() == 1){
                buf[0] = pc.getc();  // dummy read
                time_enter_mode();
                counter = SHOW_KEY_PROMPT;
            }
            pc.printf("                                                                 \r");
        } else {
            wait(1.0);
        }
        if (userSW == 0){
#if defined(USE_LCD)
            lcd.locate(0, 0);    // 1st line top
            //          12345678
            lcd.printf(" Enter  ");
            lcd.locate(0, 1);    // 2nd line top
            //          12345678
            lcd.printf("  Sleep " );
#endif
            pc.printf("\r\nEnter Deep Sleep Mode, please push RESET to wake-up\r\n");
            wait(1.0);
            myled = 0;       
            deepsleep();
        }
    }
}