Using Magix USB-Videowandler 2 on Linux

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Videowandler 2 is an USB analog video capture card. There is no official driver support for Linux and the device does not work when you plug it in. According to lsusb, the device is Afatech, which is totally wrong. The kernel only loads modules for USB audio - and this is the only thing that works (the audio input appears as a separate sound card).

Videowandler 2 is based on eMPIA 2861 USB chip. Video conversion is done by SAA7113 and audio conversion by EMP202. The IDs of the device are 1B80:E349. When opening the case, you may find printed on the board UB317 Ver:A or UB315 Ver:C. The latter my be identical to Kworld UB315 but I’m not sure.

Magix USB-Videowandler 2 board. Photo by Christian Enders.

Turn RTL-SDR dongle into RTL2832U universal board

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The most popular RLT2832U dongles are the ones with E4000 and R820 tuners. This is due to the high frequency range these tuners have. Elonics E4000 covers 52 to 2200 MHz with a gap at about 1100 MHz and Rafael Micro R820T covers 24 to 1766 MHz.

But there are also RTL2832U based dongles with other tuners. One example is FCI FC2580 tuner (found in Trust 16738 dongle) which is capable of receiving 146 - 308 MHz and 438 - 924 MHz, limiting its use to DVB-T only! It can't even receive FM radio 88 – 108 MHz.

If you’re having such a dongle don’t throw it away. There are situations when you don’t need a tuner at all (the direct sampling mode of RTL SDR that allows direct reception of signals on frequencies lower than 28 MHz). There is also the possibility of changing the existent tuner with, for example, a satellite receiver tuner that will receive 950 to 2150 MHz.

Configure WAN port on OpenWRT/LEDE

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OpenWRT/LEDE are Linux based, embedded operating systems for networking devices. Besides being open source, they are highly configurable and versatile. This post will show how to configure one of the LAN ports as WAN input for xDSL routers. The problem with xDSL routers (mainly based on Boadcom platform) is that there are no opensource DSL drivers, so this function does not work.

Anyway, many DSL routers are in fact better platforms, with improved hardware, than ordinary routers. If you want to connect the router to wired LAN internet this is what you should do. I've done this on a router with LEDE Snapshot installed (the difference is that snapshots do not come with web interface preinstalled). If you have a regulare release, you can skip LuCI installation, as you already have access to the web interface of the router.

Install OpenWRT/LEDE on P.RG AV4202N router

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AV4202N is an xDSL modem and WiFi router based on the BCM6368 SoC manufactured by Broadcom. The CPU has 2 cores running at 400 MHz, with 64 MB RAM and 16 MB flash memory. It also has 2 USB 2.0 ports and 2 WiFi internal antennas.

Currently, although the BCM63xx platform is supported by OpenWRT, there are no releases for this device. Neither LEDE Project has released a stable build for this device, but they are offering a development snapshot [3]. The problem with LEDE snapshots is that they don't work out of the box without additional software packages (you don’t get any web interface).

But, LEDE can’t be installed on the device due to the locked bootloader. This article will show you how to use JTAG to install a different bootloader that can be used to flash OpenWRT/LEDE firmware. Part 2 details LEDE configuration and internet connection.

Note! If the mentioned device was offered to you by an ISP for xDSL internet access, doing what is described next will void the warranty of the device and make it unusable. You should not attempt to change firmware in this situation. Third party firmware does not support xDSL!
Install OpenWRT/LEDE on P.RG AV4202N router

Generate good looking PCB artwork from KiCAD

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KiCAD is probably the most complete opensource EDA suite. It comes with a schematic editor, a PCB designer and a 3D viewer. PCB designs can be exported to multiple formats or printed directly from the software. Although the plotting (printing) options are quite advanced, there aren't options for overlaying different layers with different colors.

This tutorial will show you how to create PCB artwork that looks good on display or print and that is intended only as a guide to the reader, not as a source for manufacturing PCB. The result will be a greenish PCB (or any color you want) with silkscreen on top of it. This is probably something you already seen in electronics publications.

There are many ways of doing this. All you need to start are the PDF files plotted by KiCAD and some image editing software (I prefer opensource tools: GIMP or some ImageMagick scripting).

Generate good looking PCB artwork from KiCAD