1 Reply Latest reply on Aug 24, 2015 2:42 PM by PabloM_Intel

    Edison Mini Breakout, connect Battery to RTC


      Hey there,


      I'm trying to connect a coin battery (3V) to the built-in RTC of the Intel Edison, so it keeps the time even when the board gets disconnected from a power supply for hours. The battery is similar to the one recommended in https://communities.intel.com/message/298632.

      I'm using the Mini Breakout board and according to the Hardware Guide for it, V_VBAT_BKUP is on J18 - Pin 5. As suggested in https://communities.intel.com/message/256947, I connected the + pole of the battery to the pin.

      The board is running ubilinux. Setting and reading the RTC using hwclock works fine, if I use the --directisa flag. However the RTC gets reset if I poweroff the board and restart it.

      The battery is new and I verified that it's still full.


      Here's the content of /proc/driver/rtc

      root@warehouse-edison:~# cat /proc/driver/rtc

      rtc_time        : 15:40:00

      rtc_date        : 2015-08-24

      alrm_time       : 00:00:16

      alrm_date       : 2000-01-02

      alarm_IRQ       : no

      alrm_pending    : no

      update IRQ enabled      : no

      periodic IRQ enabled    : no

      periodic IRQ frequency  : 1024

      max user IRQ frequency  : 64

      24hr            : yes

      periodic_IRQ    : no

      update_IRQ      : no

      HPET_emulated   : no

      BCD             : yes

      DST_enable      : no

      periodic_freq   : 1024

      batt_status     : okay


      What am I missing? I appreciate any help.


        • 1. Re: Edison Mini Breakout, connect Battery to RTC

          Hi MinorFixes,


          Have you tried this same connection using the regular Yocto image instead of Ubilinux? Most tests with RTC have been made using the Yocto image, so I would suggest you to try it. If what you want to do is to power the Breakout Board with a rechargeable battery, you can also do that via J2. The battery will be recharge every time the board is supplied via J21 or J22.