In one of my earlier blog posts I reported that occasionally the HABpanel will disconnect from the server. Turns out it's not HABpanel, but it's the Pi itself which is causing the trouble. Part of the problem why it took me so long to investigate is that the display is in the kitchen, and someone had to have a look and spot the small red error message. To work around that problem, I hooked the device up in the network monitoring, and had an alarm triggered when the device is not reachable. Sure enough, that happens occasionally.
Because I moved /var/log to a small RAM disk to avoid wearing out the SDcard, all logs are lost once the device is rebooted. Had to bring keyboard and mouse to the kitchen in order to save the logfiles once the device was no longer reachable over the network.
Continue reading "Reboot the Raspberry Pi on network failures (brcmfmac: brcmf_cfg80211_scan: scan error -110)"
The new Raspberry display works nice, but the screen is too bright. At night in the kitchen it enlightens the entire room - unnecessarily. Since I'm using the original Raspberry Pi 7" touch display, the brightness can be controlled in /sys/class/backlight/rpi_backlight/brightness. This "file" can hold a value from 0 (display off) to 255 (full bright).
Continue reading "Dim the Raspberry Pi screen"
After upgrading Ansible to version 2.8.3, the following deprecation warning appeared many times:
[DEPRECATION WARNING]: The TRANSFORM_INVALID_GROUP_CHARS settings is set to allow bad characters in group names by default, this will change, but still be user configurable on deprecation. This feature will be removed in version 2.10. Deprecation warnings can be
disabled by setting deprecation_warnings=False in ansible.cfg.
[WARNING]: Invalid characters were found in group names but not replaced, use -vvvv to see details
Wow, previously valid names in my hosts.cfg file are soon invalid? What's going on here?
Continue reading "Ansible: TRANSFORM_INVALID_GROUP_CHARS deprecation warning"
After upgrading Ansible to version 2.8.3, the "apt" module started spitting out deprecation warnings:
TASK [common : basic packages] ***********************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
[DEPRECATION WARNING]: Invoking "apt" only once while using a loop via squash_actions is deprecated. Instead of using a loop to supply multiple items and specifying `name: "{{ item }}"`, please use `name: ['vim', 'screen', 'rsync']` and remove the loop. This feature will be removed in version 2.11. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
ok: [hostname] => (item=['vim', 'screen', 'rsync'])
Continue reading "Ansible: "apt" module and loops"
The new display showing HABpanel works quite nice. But occasionally the fullscreen browser will lose the network connection. As far as I can see, it's not a Wi-Fi problem of the Raspberry Pi, but still annoying: in the morning the browser shows a small red warning that the connection to the openHAB server is lost, time is still correct, but temperature and the status of other devices is outdated. To fix that, I have to leave fullscreen mode, hit reload - and then there is no keyboard for going into fullscreen mode again (that's using the F11 key).
Continue reading "Occasional HABpanel disconnect from the openHAB server"
Pavlo recently pointed out that the pg_sleep() function in PostgreSQL has two alternatives: pg_sleep_for() and pg_sleep_until().
What do they do?
Continue reading "SELECT pg_sleep_until('#800Monies');"
The PostgreSQL Project is present with a booth at FOSDEM ever since 2007. Since 2008 we organize a Devroom, since 2013 we have our own PGDay on the Friday before FOSDEM. This year marks the 8th FOSDEM PGDay.
This blog post presents useful information about the PGDay, the booth and Devroom at FOSDEM.
Continue reading "PostgreSQL @ FOSDEM 2020"
The Raspberry Pi with the touch display for the home automation system is coming along nicely. One problem to solve: how to display the openHAB HABpanel, and which browser to use?
Firefox and Chrome don't run on Raspbian. However "Chromium" (the open source part of the Chrome browser) is. That's a good start. But how to start the browser automatically, and in full screen?
Continue reading "Automatically start a fullscreen browser on a Raspberry Pi - show openHAB HABpanel"
Recently I installed a Raspberry Pi with Raspbian, and attached a touchscreen to it. The device is supposed to work as a display for our openHAB home automation system. All nice and shiny, except the Pi occasionally disconnects from the Wi-Fi - apparently in order to safe power. Once the network device is needed, the Wi-Fi is reconnected. That is the default setting.
That is quite annoying, because the HABpanel will lose it's connection to the openHAB server, and no longer show widget updates. Some widgets like "time" will just continue to work, but other widgets like status of the washing machine, or the current outside temperature just show the last state, and never update.
Continue reading "Raspberry Pi: disable Wi-Fi powersave, and stay connected all the time"
Previously I blogged about how the washing machine and the dryer are integrated into the openHAB home automation system.
For a while I had a standard "Dummy" widget in HABpanel, but that didn't look very nice, was very standard, and the different icons for different states don't really work. When I started integrating another Raspberry Pi with a touch screen (blog post to come), I refreshed the HABpanel, added another dashboard, and along the way I wrote a new "Template" widget for the washing machine and the dryer.
This project had a number of small goals:
- Make the headline (the name) bigger - in the dummy it seems to be hardcoded, and very small
- Use the proper icon for every Item state (running, finished, standby)
- Change the background color of the widget according to the state of the Item
Continue reading "openHAB: widget with multiple different background colors"