Wayland Screenshare Apr 10, 2021 Desktop screen sharing in Wayland (Chrome + Fedora) Fedora 33 with Gnome 3.38.x using Wayland will only let you share a single window or tab. Full desktop screen share does not work out of the box. Sharing your screen via Google Meet results in a black or blank screen. To fix this, upgrade the version of pipewire and enable experimental WebRTC PipeWire support in Chrome flags. dnf install pipewire-0.3.24 Go to chrome://flags/#enable-webrtc-pipewire-capturer, set to “Enabled” and restart Chrome. ...
Installing awscli on Synology Nov 01, 2020

This will allow you to do useful things such as syncing a S3 bucket to disk. Working on my DS918+.

  1. Add a custom package source for cphub.net. From Package Center, select Settings -> Package Sources and add http://www.cphub.net.

  2. In the Community packages section, search for Easy Bootstrap Installer and install ipkg (not opkg).

  3. With ipkg now installed, use this to install Python 2.7.

    sudo /opt/bin/ipkg install py27-setuptools
  4. Then install pip and awscli.

    sudo /opt/bin/easy_install-2.7 pip
    sudo /opt/local/bin/pip install awscli
Proxmark3 Firmware Installation on Fedora Mar 24, 2019
  1. Install dependencies

    sudo dnf install readline readline-devel libusb libusb-devel qt4-devel ncurses-devel arm-none-eabi-gcc arm-none-eabi-newlib pcsc-lite pcsc-lite-devel
  2. Install blacklist rules

    sudo cp -rf driver/77-mm-usb-device-blacklist.rules /etc/udev/rules.d/77-mm-usb-device-blacklist.rules
    sudo udevadm control --reload-rules
  3. Build

    make clean
    make all
  4. Then proceed with flashing.

DFRobot I2C LCD1602 (Gravity) Jan 12, 2019
DFRobot LCD1602 I2C module with with blue background.

DFRobot LCD1602

DFRobot LCD1602 I2C module with with blue background.

This LCD is a small I2C display module that has a 16x2 character display. The text appears white on blue, with a dimmable backlight. Information and libraries for this chipset were a little hard to find, so I have listed some resources here for reference.

The officially provided library appears to be some monochromatic re-implementation of Seeed Studio’s Grove LCD RGB Backlight that can be found at: https://github.com/Seeed-Studio/Grove_LCD_RGB_Backlight

I could not find a datasheet for this chipset, however I came across the information sheet which had some broken links. (http://www.west-l.com/uploads/tdpdf/104030001_eng_tds.pdf)


  • This display uses a AiP31068L chipset, that is not compatible with the more common HD44780 chipset.

  • There are actually two I2C devices in the module, one for the backlight, and one for the character display. Their addresses are:

    #define LCD_ADDRESS     (0x7c>>1)   // character 0x3e
    #define RGB_ADDRESS     (0xc0>>1)   // backlight 0x60
  • Note for the Arduino Uno, the I2C pins are A4 (SDA) and A5 (SCL).

RC Servo Starter Kit Jan 04, 2019

Getting started with a RC setup that works is harder than it looks, due to the number of parts and specifications required. A common starter requirement is to control a few servos remotely. These are my notes for the components and considerations required to get started.

Fedora 28 usermod groups fails Jan 01, 2019

After updating to Fedora 28, adding a user to a group fails with:

(Wed Jan  2 00:33:14:341408 2019) [sss_cache] [confdb_get_domains] (0x0010): No domains configured, fatal error!
Could not open available domains
usermod: sss_cache exited with status 2
usermod: Failed to flush the sssd cache.

As suggested, the issue is due to sssd not being configured. If you are not using sssd for authentication, simply remove it and try adding the group again.

sudo dnf remove sssd
sudo usermod -aG dialout frank
HackRF One Initial Setup Dec 29, 2018


  1. Install development tools and drivers

    sudo dnf install hackrf hackrf-devel
  2. Get latest firmware from https://github.com/mossmann/hackrf/releases

  3. Update firmware (see https://github.com/mossmann/hackrf/wiki/Updating-Firmware)

    cd firmware-bin
    hackrf_spiflash -w hackrf_one_usb.bin
  4. Check firmware version

    $ hackrf_info
    hackrf_info version: unknown
    libhackrf version: unknown (0.5)
    Found HackRF
    Index: 0
    Serial number: 0000000000000000a06063c8220a635f
    Board ID Number: 2 (HackRF One)
    Firmware Version: 2018.01.1 (API:1.02)
    Part ID Number: 0xa000cb3c 0x00534f64
  5. Update CPLD

    hackrf_cpldjtag -x firmware/cpld/sgpio_if/default.xsvf

Useful Tools

Installing GoCV Sep 11, 2018

Installing GoCV requires a few extra environment variables to be set.

Before the make install phase, set the following variables

export GOPATH=/home/frank/go
export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig
export LD_LIBRARY_PATH=/usr/local/lib64

It is also easier to install the OpenCV libraries system-wide by running make install as the root user.