RaspBee II RTC

RTC kernel module builder for RaspBee II

This repository provides a Makefile which downloads, builds and installs the RTC kernel module for the RaspBee II Zigbee shield for Raspberry Pi.

The RTC is not mandatory for the use of the RaspBee II as a ZigBee coordinator.

When the linux kernel gets updated it can happen that the RTC module build fails because it takes some time until the raspberry pi kernel headers package is updated with the new version. In this case you can repeat the build in a few days. Or get your kernel version from somewhere else (rpi-source) or try use a workaround described below.

Dependencies

Hardware

• Raspberry Pi 1, 2B, 3B, 3B+ or 4B, 5
• RaspBee II Zigbee shield
• FW version 26610700 or higher (http://deconz.dresden-elektronik.de/deconz-firmware/deCONZ_RaspBeeII_0x26610700.bin.GCF)

Additional Notes for Raspberry Pi 5 and Home Assistant

Raspberry Pi 5

add following to your config.txt

• enable_uart=1
• dtparam=uart0_console
• dtoverlay=uart0

Home Assistant

• use the Port ttyAMA0 even if it says ttyAMA10

Supported platforms

Raspbian Stretch, Buster, Bullseye and expectedly later versions

Install

0. Update Raspberry Pi and Reboot

    sudo apt update
    sudo apt upgrade
    reboot
   

1. Install dependencies

    sudo apt install i2c-tools build-essential raspberrypi-kernel-headers
   

2. Download installation archive

    curl -O -L https://github.com/dresden-elektronik/raspbee2-rtc/archive/master.zip
    unzip master.zip
   

3. Change into extracted directory

    cd raspbee2-rtc-master
   

4. Compile RTC kernel module

    make
   

5. Install RTC kernel module

    sudo make install
   

6. Reboot Raspberry Pi

    sudo reboot
   

7. Configure system time to RTC module

    sudo hwclock --systohc
   

8. Test that RTC is working

    sudo hwclock --verbose
   

   Waiting in loop for time from /dev/rtc0 to change
    ...got clock tick
    Time read from Hardware Clock: 2020/03/06 13:55:21
    Hw clock time : 2020/03/06 13:55:21 = 1583502921 seconds since 1969
    Time since last adjustment is 1583502921 seconds
    Calculated Hardware Clock drift is 0.000000 seconds
    2020-03-06 14:55:20.017097+01:00

   timedatectl
   

   Local time: Fri 2020-04-03 12:42:20 CEST
           Universal time: Fri 2020-04-03 10:42:20 UTC
                 RTC time: Fri 2020-04-03 10:41:56
                Time zone: Europe/Berlin (CEST, +0200)
           System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no

Troubleshooting

If something went wrong during install please consider the following error sources:

• Install dependencies
• Execute make without sudo
• Execute make install with sudo
• If behind a proxy make sure it is correctly configured

If you get Error Message like

make -C /lib/modules/6.1.21-v8+/build M=/home/openhabian/raspbee2-rtc-master modules
        make[1]: *** /lib/modules/6.1.21-v8+/build: File or directory not found.  Exit.
        make: *** [Makefile:17: build] Error 2

• try adding "arm_64bit=0" to config.txt, (disables 64bit) reboot and try again
• or link your kernel version lib/modules directory to existing kernel header directory in /usr/src

ls -l /usr/src
sudo ln -s /usr/src/linux-headers-6.6.20+rpt-rpi-v7l /lib/modules/$(uname -r)/build

Use the RTC

Set RTC time to system time:
sudo hwclock --systohc

Read the RTC time:
sudo hwclock -r

For more information see: https://linux.die.net/man/8/hwclock