rpi.rtc

Simple Python module to deal with DS1302 RTC on Raspberry Pi

Wire map (default conf.)

Setup

sudo apt-get -y install python3-rpi.gpio
sudo python3 setup.py install

Read RTC chip date and time

ds1302_get_utc

RPi date and time (UTC) to RTC chip

ds1302_set_utc

Update Rpi system time from RTC chip

Typically call at RPi startup

sudo date -s `./ds1302_get_utc`

One line to check RTC chip time vs system time

Since RTC store only second and not millisecond a 1s delta can occur (or more after a few days)

# drift in second
echo $(($(date -u -d`ds1302_get_utc` +%s) - $(date -u +%s)))
# human readable
echo "RTC `ds1302_get_utc`"; echo "SYS `date --utc +%FT%TZ`";