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PiFace RTC on Raspberry Pi2: still losing time on reboot!

Former Member

Hi!

 

I bought a PiFace RTC and I'm trying it on a Raspberry Pi 2 Model B. I followed the many guides I found on the internet, but I'm still having problem with the date: when I reboot, the system time is always set to Jan 1, 1970! It seems to be in a reset condition.

The I2C detects well the device at the address 0x6F, and the battery is ok.

After the execution of the .sh script as written in the PiFace RTC user guide, I set the actual date with "sudo date -s "12 jan 2016 10:30:00",

set the i2c module from raspi-config.

I triyed in so many ways but I really can't understand what I'm doing wrong!

 

Any idea would be appreciated!
Thanks,

 

Andrea.

Parents
  • 0 in reply to clem57

    Hi Clem,

     

    Thank you.

    Yes, I installed the script, either automatically (connected to the internet) and manually (procedure described in the link you provided). Unfortunately, nothing is changed..

    After installing the script with

    $ sudo ./install-piface-real-time-clock.sh

    This message appears:

    Changing /etc/rc.local to load time from PiFace Clock.
Now *reboot* and set your clock with
sudo date -s "14 JAN 2014 10:10:30"

    So, I enabled the I2C by running

    $ raspi-config

    as described in the link you provided, then I rebooted and set the date with sudo date -s ...

    Then:

    sudo reboot

    The new date seems to be not retained!

    $ date

    Gives to me:

    gio 1 gen 1970, 01.00.18, CET

    It still not working image!

     

    I checked the i2c with:

    $ i2cdetect -y 1

    this is the output:

         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- UU
70: -- -- -- -- -- -- -- --

     

    As far as I remember, this means that the PiFace RTC seems to be well detected...

     

    I really can't understand where can be the problem, what am I doing wrong?

    Thanks in advance,

     

    Andrea

  • 0 in reply to Former Member

    Do you have pullups on the I2C lines, if not you should, they will help alot

     

    about 5K-10K should work if the RTC is closs to the PI

  • 0 in reply to Robert Peter Oakes

    Just looked at the board and it appears to have some so perhaps a different problem ??

  • 0 in reply to Robert Peter Oakes

    Thanks Peter,

     

    yes, perhaps it's a different problem.

     

    For testing purpose, I tryied to set the date with:

    sudo date -s "14 jan 2016 08:55:30"

     

    then I copy the time to the RTC with:

    sudo hwclock -w

     

    Then I read the RTC with:

    sudo hwclock -r

     

    Ok, the time displayed is correct.

     

    After that, I shut down, wait for five minutes and I power up.

     

    I try to read the RTC once more:

    sudo hwclock -r

     

    It gives:

    gio 1 gen 1970, 01.00.31, CET

     

    and sudo hwclock -r gives:

    hwclock: The Hardware Clock registers contain values that are either 
invalid (e.g. 50th day of month) or beyond the range we can handle (e.g. Year 2095).

     

    So the time has not being retained! I really don't know where the problem can be image

    Please help!

  • 0 in reply to Former Member

    #=======================================================================

    # NAME: start_on_boot

    # DESCRIPTION: Load the I2C modules and send magic number to RTC, on boot.

    #=======================================================================

    start_on_boot() {

      echo "Changing /etc/rc.local to load time from PiFace Clock."

      # remove exit 0

      sed -i "s/exit 0//" /etc/rc.local

     

      if [[ $RPI_REVISION == "1" ]]; then

      i=0 # i2c-0

      else

      i=1 # i2c-1

      fi

     

      cat >> /etc/rc.local << EOF

    modprobe i2c-dev

    # Calibrate the clock (default: 0x47). See datasheet for MCP7940N

    i2cset -y $i 0x6f 0x08 0x47

    modprobe i2c:mcp7941x

    echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-$i/device/new_device

    hwclock -s

    EOF

    }

    The script above is not setting /etc/rc.local correctly. Please show the contents here. Ty

    Clem

  • 0 in reply to clem57

    Hi Clem,

     

    where have to be placed the script you posted? Is it automatically executed at the startup?

     

    My /etc/rc.local contains the code below (is it correct? Perhaps some problems here?)

    _IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi


modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s
modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#Andrea
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
( sleep 2; hwclock -s ) &

modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#added by myself
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
sudo hwclock -s

modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#added by myself
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
sudo hwclock -s
modprobe i2c-dev

# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s
modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

     

    Thanks again!

Reply
  • 0 in reply to clem57

    Hi Clem,

     

    where have to be placed the script you posted? Is it automatically executed at the startup?

     

    My /etc/rc.local contains the code below (is it correct? Perhaps some problems here?)

    _IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi


modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s
modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#Andrea
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
( sleep 2; hwclock -s ) &

modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#added by myself
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
sudo hwclock -s

modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

#added by myself
echo mcp7941x 0x6f > sys/class/i2c-adapter/i2c-1/new_device
sudo hwclock -s
modprobe i2c-dev

# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s
modprobe i2c-dev
# Calibrate the clock (default: 0x47). See datasheet for MCP7940N
i2cset -y 1 0x6f 0x08 0x47
modprobe i2c:mcp7941x
echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device
hwclock -s

     

    Thanks again!

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