Deadly Cheap Power Supply

This is why I open all power supplies before using them if at all possible.
Mounting this supply would have put the housing at mains voltage. That’s also why you should never forget the protective earth connection.

Open Source Brushless Servo

The odrive is a open source high performance brushless servo platform based on RC BLDC motors. Great Stuff!

Key Specs

  • Two motor channels.
  • 24V, designed for more than 100A peak current.
    • 48V version just released.
  • DC-DC converter, for brake resistor or energy storage.
  • Encoder feedback for arbitrarily precise movements.
  • Supports power regeneration.
  • Optional use of a high power density battery means you can achieve >1kW peak power output with only a modest power supply.
  • Open source: HardwareSoftware


  • USB Serial port — PC, BeagleBone, RaspberryPi, etc.
  • CAN — CANOpen and CiA 402 is a possibility.
  • UART — Arduino, mBed, etc.
  • PWM — RC Recievers, Arduino, etc.
  • Step/direction — Existing motion controllers
  • Some general purpose digital and analogue pins


  • Many types of command modes
    • Goto (position control with trajectory planning)
    • Position commands
    • Velocity command
    • Torque command

GCODE from SVG in the Browser

Jscut is an open source browser based GCODE generator that uses SVG as an input.

Jscut seems to be the predecessor of LaserWeb by the same developer and several other contributors that is focused on controlling lasercutters but does basically the same with a more polished interface.


Video Streaming for ARM

UV4L was originally conceived as a modular collection of Video4Linux2-compliant, cross-platform, user space drivers for real or virtual video input and output devices (with absolutely no external difference from kernel drivers), and other pluggable back-ends or front-ends.

It has evolved over the years and now includes a full-featured Streaming Server component with a customisable web UI providing a set of standard, modern and unique solutions for encrypted live bidirectional data, audio and video streaming, mirroring or conferencing over the web and for the IoT . Since recent releases UV4L has also been providing a RESTful API for the developers who want to implement their custom applications.

HDMI Capturing

The Video4Linux2 uv4l-raspicam driver for Raspberry Pi  has been extended to support the TC358743 HDMI to MIPI converter chip. This chipset is often found in the B101 capture boards made by Auvidea.

Video broadcast via Wifi

This projects uses a interesting DIY approach to broadcast video via wifi. Video transmitter and receiver are never directly associated. The receiver is put into monitor mode. This results in a transmission that behaves more like a analog solution. With a weaker signal there is not an immediate disruption of the transmission but a degradation because of packet loss.


Wifibroadcast – Analog-like transmission of live video data

HowTo Enable the RaspiCam in Octoprint

First, if you haven’t already, activate the camera in raspi-config. Login via SSH type “sudo raspi-config” select “Interfacing Options” and enable the camera.

Configuring the camera

Now edit “sudo nano /boot/octopi.txt” uncomment the camera=”auto” line and change it to camera=”raspi”. Uncomment camera_raspi_options=”-fps 10″. These settings configure the camera to provide and image in the format 640×480@10fps. If you would like to change that check the available options at:

Enabling the camera in the octoprint browser interface

In the browser click on the little wrench in the top bar to open the settings dialog. Select “Webcam & Timelapse”. Set the “Stream URL” parameter to “http://octopi.local:8080/?action=stream”. Obviously change the hostname if you have configured it to something different.

Finally restart octoprint for the changes to take effect.

Reverse Port Forwarding

On the remote computer

Create a ssh connection to the home computer and start a local ssh server listening on port 2210 on it.

 ssh -R 2210:localhost:22 homeuser@[home-ip]

add –C to activate compression

add -f -N to put the process into the background

On the home computer

Connect to the local ssh server created by the remote connection.

ssh -p 2210 remoteuser@localhost