Tech Tinkering

New home for Miscellaneous Tech Projects/Procedures

We'll see how these shakeout ... I suspect there will be some reorganization and categorization of topics (e.g. smarthome, privacy) as worthwhile articles are salvaged from

In the meantime, we'll try expandable blocks of Notes to Self on this page to see how new Google Sites works for this.

The notes on this page will likely be very random and may well be incomplete or a total mess!

Putting Raspberry Pi Monitor to Sleep (DPMS) [done]

Fix for a longstanding Raspberry Pi annoyance: Getting the monitor into powersave mode after a period of idle time - turning off the backlight.

Here's a quick tweak that seems to work fine on native HDMI and VGA (via adapter*) monitors. Hopefully helpful to others.

Background: I've played with Linux Power Management commands, utilities, screen savers and such in attempts to get Pi's to turn off (standby) monitors when idle. I recently hit upon a couple of Raspberry Pi config option that seems to do the trick - not really sure when/where it appeared, but it does switch off the HDMI when Display Power Management (DPMS) is triggered, as opposed to simply blanking the screen. Works on Raspbian Stretch & Buster and recently on RaspOS

Fall 2021 Update: In spite of a recent Buster Update ... I STILL manually adjust /boot/config.txt & /boot/cmdline.txt to get HDMI into standby mode. Works on RPI 4 too!


Oct 2018 Step-by-step (Original Post)

The fix involves editing a couple of key configuration files - as always remember to make a backup copies before type-o'ing in these files!
Use sudo to edit files in boot partition *and* be careful!

  1. Edit /boot/config.txt (RPi's main System Config File)

      • Add the following line to force HDMI output to switched off when DPMS is triggered. This config option was not explicitly defined in my Raspbian (Stretch) config.txt - apparently defaults to 0/off.


I added this line below hdmi_mode in config.txt, but it probably doesn't matter.

See complete details in There are some notes/considerations.

  1. Make sure Screen Savers are installed/configured to take advantage of hdmi_blanking.

    1. For Console Mode (no Desktop UI) set console blanking ...

      • Check current setting of consoleblank kernel parameter, it sets the inactivity time. It defaults to zero (returns 0)

$ cat /sys/module/kernel/parameters/consoleblank


      • Edit (sudo) /boot/cmdline.txt to set time in seconds to turn off monitor when Pi is in console mode.
        Carefully add the string "consoleblank=<numsec>" to /boot/cmdline.txt - MUST be a single line text file like this:

$ cat /boot/cmdline.txt

dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 consoleblank=300 root=/dev/mmcblk0p7 rootfstype=ext4 elevator=deadline rootwait

    1. For Desktop GUI set Display Power Management (DPMS) via screensaver or power manager applications - you may need to install these.

sudo apt-get install xscreensaver

sudo apt-get install xfce4-power-manager

See RPI Screensaver doc @ for complete details.

    1. Reboot and check your work!

As they say in IT - Works for me! Hope it works for others too.

Couple of random notes:

Garmin eTrex 10: How to Add Coordinates to Compass Display [done]

Here's a quick Garmin eTrex 10 techno adjustment that seems to reduce aimless wandering when elementary students tackle GPS activities like Hide-N-Seek. In a nutshell: Add current location (GPS coordinates) to the eTrex 10 compass display to provide realtime tracking of longitude/latitude changes.

The following setup procedures adjusts eTrex 10 Compass Display Screen. Here's a Picture of the Modified eTrex Display (New Google Sites won't embed images in these text boxes!)

Setup - Approx 40 Seconds/Unit to set this up

  1. Select "Profile Change" then select "Recreational"

  2. Select "Compass" then press Menu button (on left)

  3. Highlight/Select "Change Dashboard" then select "Large Data Field"

  4. From Compass display (again) press Menu button

  5. Highlight/Select "Change Data Fields" then select top field on screen

  6. Scroll thru Fields (alphabetically) to find/select "Location (lat/lon)"

  7. Hit Back button to return to compass display

Usage - Students navigate using compass display.

  1. Select “Where To?” then select “coordinates”

  2. Enter coordinates of desired destination using Thumbstick
    - remember to hit

  3. Hit Back button (Upper right) until main screen appears

  4. Select “Compass” - you should see pointer on Compass and current Location

  5. Wander until Location on Compass = Target Destination!

Some handy Garmin eTrex 10 links

That's it - hope it helps

Migrate from Smartthings V1 hub to Aerotec [done]

We will see how this all works out: Samsung/Smartthings sent an email offer to get an Aeotec hub for $35. Appears that ST is getting out of the hardware biz? Anyhoo, our ST hub is pretty old, v1 from 2014 or ..... so .... I bought the new hub. Will attempt to keep ST devices going for a few more years - looks easier than making a zigbee/z-wave gizmo out of a Raspberry Pi! This chatter may become a page of its own ...

Objective: Migrate ST V1 home hub and devices to Aeotec


Step by Step (apparently no migration tool for ST Hub V1 to Aeotech .... soooo hereeeee weeee goooo)

  1. Inventory: In our case, we have Smartthings AND Homebridge (see homepi project). We use ST for some automation & remote access. but native homekit (Apple Ios) around the house ... e.g. - "Hey Siri, turn on the light"

    • The Smartthings Mobile App has always been total junk ... no config print or download/restore. I guess we make record (by hand) of config
      I snapped a iPad screenshot of the stuff in the menu bar - this will be a MAJOR prob for large configurations:

      • Rooms, Devices, Scenes, Automations, SmartApps & mainscreen to show which devices were in which rooms! Yeeesh!

      • Main Screen to show which devices were in which rooms!

    • Via the ST Developer Site ( ...

  2. Simplify: In our case (destined for apple homekit), reduce the number of devices that are directly controlled by ST hub.

  3. Resubnet: Yeeesh! HomePod pretty much requires iOS devices on the same subnet as HomePod and all those creepy IoT thingies!

      • Managed to keep our main systems w/ data isolated - Mac's, PC's, Linux & MIPi, of course

      • Had to move HomePi to 'Things' subnet

MoviePi: Fix YouTube Kodi App [incomplete]

Background: YouTube Add-on on Kodi stopped working in past year or so. I simply stopped using it on my parent's MoviePi. Created another MoviePi for our house and YouTube seemed to work fine ... FOR A WHILE. I'll be back to figure this out and clean this up


Duplicate LIFX Bulbs in Homekit [solved]

Another cleanup item

The Problem: One of our LIFX (wifi) bulbs appears to have paired with Smarttings AND Homekit. Shows up twice in home app.

This was easily fixed when I moved from the Smartthing Hub to Aerotec - THERE WAS NO MIGRATION TOOL! I simply reset the LIFX bulbs and now use native HomeKit (Apple), never moved them back to Smartthings! See below ... we now now using Smarthings for as little as possible ... in our home, only to control original Smartthings devices (Centralite Zigbee) or Z-Wave.

Factory Reset article here -

Hue V1 Bulb Factory Reset [solved]

The Big Issue: Our "Smarthome" is getting outdated. Hubs and devices purchased during the dawn of IoT are slowly being dropped from support

Little Issue: We have a lone v1 Hue Light bulb that was paired directly to a v1 Smartthings hub. I needed to factory reset it and move to the Hue Hub in an attempt to get a few more years out of it. Here's my How-to-collection and hopefully a procedure that works

Circa 2017 (some broken links):

Easier than the last time I tried this ... BUT ...

ST "Smart Lighting" app is now gooffed upped! When I try to adjust ANY Automations in the Smart Lighting App - I see "Something Went wrong. Please try to reinstall the SmartApp again" ... which is a pain in the arse because we have all sorts of complicated lighting automations that were really hard to define on the stupid ST app in the first place.

Ack! Rebooted the hub, reset all IOS ST apps, still the same ... will have to hand-record all automations and delete, re-add the "Smart Lighting App"(This is going to turn out bad, I just know it!) . The topic is on fire on the ST support board @ I put a watch on it and filled my email inbox!

I basically recreated all of the Smart Lighting App rules using the 'Automations' feature on the new ST app. Really wasn't that bad to do. I'll bet the ST folk are trying to get others to use this feature and get rid of the smart apps. They should just say something on the forum!

Homebridge Cameras [incomplete]

Homebridge Tweaks

Camera Plugins:

Ghads Zooks - 20 options?!

Urls used to interface w/ DLink cams @

Handy RTSP Directory @