Recent content on KittenLabs
What is it? █████████ ███ ███ ███░░░░░███ ░░░ ░░░ ███ ░░░ ██████ █████ ████ ██████ █████████████ ██████ ████████ ████ ██████ ░███ ░░░░░███ ███░░ ░░███ ███░░███░░███░░███░░███ ░░░░░███ ░░███░░███ ░░███ ░░░░░███ ░███ ███████ ░░█████ ░███ ░███ ░███ ░███ ░███ ░███ ███████ ░███ ░███ ░███ ███████ ░░███ ███ ███░░███ ░░░░███ ░███ ░███ ░███ ░███ ░███ ░███ ███░░███ ░███ ░███ ░███ ███░░███ ░░█████████…
We recently stumbled across a broken Marantz UD5007 Blu-ray/SA-CD/DVD/CD player for a really low price. The previous owner reported the power supply to be broken, and a professional repair service had given absurd quotes for troubleshooting/repair. When plugged into the wall, the player would only blink the red standby LED indefinitely and never turn on/make any noises. Making our lives a lot…
What is it? This project is a Debian Linux-based operating system for computers, either PCs or Raspberry Pi’s. It is designed to take the URL to a website and display it in fullscreen, without any UI elements. There are several similar solutions for this task, but many suffer from issues like reliability issues due to broken SD cards, crashing browsers, etc.
Result Motivation Modern speakers require a lot of DSP magic to sound as good as they do. Speakers traditionally needed to be built very carefully to achieve a very flat frequency response and as few artifacts as possible. These days, many mobile devices like phones, laptops, etc. do a lot of digital signal processing in software in order to make tiny speakers output a lot of sound. Many different…
Backstory At the 38th Chaos Communication Congress (38C3) benjojo gave a very interesting talk titled: “ Going Long! Sending weird signals over long haul optical networks ” Spoiler/tl;dw: Ben is showing that common SFP fiber optic transceivers are mostly “dumb” devices, just converting digital electric signals into light (and vice-versa). He used this to transport Toslink…
What is it? The 16bit-LVDS-FX3-Framegrabber is a Cypress FX3 SuperSpeed Explorer Kit-based PCB, which can digitize a parallel 16bit digital video stream from a commercial image sensor. It exposes a USB 3.0 UVC (“webcam”) device to the operating system. Video signal is accepted on a 50pin SCSI-II connector as parallel LVDS. Required signals: DATA_VALID HSYNC VSYNC PIXCLK DATA0 through…
Motivation A while ago, the SolarCamPi project, a off-grid solar-powered WiFi camera, was built. In this project, a Raspberry Pi Zero 2 W is being booted into Linux, a picture is taken, WiFi connectivity is established and the Pi is shut down again (to save power). This repeats every couple of minutes to always deliver a fresh image to a cloud service.
Why? Wireless networks can authenticate clients using a surprising number of different mechanisms. The typically used and most well known is WPA(2)-PSK (also called -Personal), which is the “classic” mechanism with a known passphrase. WPA-Enterprise allows an access point to forward the authentication request to a RADIUS server. This radius server then uses the Extensible…
Why? Sometimes using Windows is inevitable. Windows 11 has gotten pretty annoying with loads of weird default settings, ads, tracking and a general infantilization of users. This is my personal collection of registry tweaks, which I apply to fresh Windows 11 installations to make the system more usable. Most tweaks were either created by me personally or have a comment with a source/link. You…
Why? Many people already use custom domains for their blog, e-mail, etc. As the format of e-mail and fediverse accounts is basically identical, it would be ideal to be able to find Fedi users via their “normal” username@domain.tld address: Background When searching for a specific account via the search function in (for example) Mastodon, the server executes a HTTP GET request like…
macOS speed test Your browser does not support the video tag. iOS speed test Your browser does not support the video tag. Background info Modern versions of macOS and iOS (starting with macOS Ventura/13) ship with NVIDIA/Mellanox ConnectX network drivers. AppleEthernetMLX5 is included by default and can be used with any NVIDIA/Mellanox ConnectX-4, 5 and 6 network card:
Real gaming router This is part 2 of the “Real gaming router” series of blog posts. Read Part 1 / Real gaming router first. Why? If you’ve seen part 1 of the “Real gaming router”, you know that the game performance in GTA Vice City was a bit lacking. As a quick reminder, this is what the game looked like before any mods: Your browser does not support the video tag.…
Update, 18th March 2024 Read Part 2 / Router overclocking for an update on performance. What is it? A TP-Link wireless router, with an external AMD Radeon GPU connected via PCIe, running Debian Linux and playing games: What makes this router so special? TP-LINK’s TL-WDR4900 v1 is a very interesting WiFi router: Instead of the typical MIPS or ARM CPUs found in normal WiFi routers, the WDR4900…
Windows can use normal TLS certificates to authenticate RDP sessions. This gets rid of the annoying RDP certificate warnings: Using real, signed certificates for RDP offers a way to enhance security (preventing man-in-the-middle attacks) and reduce alert fatigue. Note: If you’re using ACME/Let’s Encrypt locally on Windows, skip all SSH stuff and just take some inspiration from the…
A 20 port USB-C charger in use What is it? The 20 port USB-C charger can charge up to 20 USB-C devices from a single USB-C supply. Each charging port can deliver up to 7.5W (5W if all ports are in use) and is individually current limited. The charger was developed to charge a whole litter of Blinkekatzen from a single supply.
Used Gigabyte MJ11-EC1 mainboards are available for low prices on ebay and at other hardware vendors. After buying a couple of MJ11-EC1 boards for a homelab cluster project, I ended up with a dead board. The server would turn on, BMC was reachable and could be used, but the server itself would never POST. There were no POST codes, no beeps and no signs of life whatsoever. Memory was tested (and…
What is it? The NVMe BIOS Option ROM is a heavily modified version of iPXE , which can be integrated into a computers BIOS (or provided via a PCI card, USB flash drive, SD card, etc.). It allows x86 computers to boot from NVMe devices attached via PCIe, even on devices which are much older than NVMe itself. The NVMe implementation was ported from SeaBIOS and modified to work with iPXE.
What is it? This tiny mod board can be used to add 2.5 Gigabit Ethernet to devices that have PCIe available internally. It can for example be used to replace an existing 1 Gigabit PCIe NIC in embedded devices, upgrading them to 2.5 GbE connectivity. The board is based on the cheap and well-supported RTL8125BG PCIe 2.5 GbE Ethernet controller.
Wild Blinkekatzen in their natural habitat What is it? Blinkekatzen are a replacement PCB for commercially available silicone LED lights. The lights usually contain a battery, some RGB LEDs and an optical diffuser in a soft cat shaped translucent silicone housing. The light emitted by the LEDs hits the diffuser and lights up the outer cat shaped silicone shell.
What is it? USB-C PD trigger board with integrated high-power Step-Down converter to 16V. This board will negotiate 20V, 5A (100W) against a USB-C PD power supply and convert the bus voltage into 16V. This can be used to power various laptops like ThinkPad T41, T43, etc. Electronics Enclosure To ensure a full 100W can be delivered continuously a bit of cooling is required. For this project cooling…
What is it? HomeSwitch-4 is a small, low-cost, open hardware, USB-C powered 4-port Gigabit ethernet switch, running OpenWRT. It’s VLAN-capable and can handle simple VPN and routing applications (CPU connected via 100 MBit/s). It uses a cheap Allwinner V3s SoC (Cortex A7, 64MB DDR2) and a Realtek RTL8367RB switch chipset. The design is optimized for automated assembly. Features OpenWRT…
What is it? DC UPS is a lithium battery-powered uninterruptible power supply, which can provide backup power to devices like routers, switches, modems, single board computers, etc. In contrast to commercially available UPSes, it uses off-the-shelf 18650 Li-Ion cells and outputs DC voltage directly. This is significantly more efficient than providing AC power through an inverter.
Features Bright, sunlight readable OLED display Infinity constrast ratio Support for GIF animations WLAN AP support Web interface for management of animations Automatic brightness adjustment 8h+ runtime Links Hardware : KiCAD design files Firmware : ESP-IDF source code
What is it? 3D-printable adapter, which fits into commercial thermal cameras and adds a 18mm ZnSe CO2 laser lens to the optical path. This greatly improves the imaging quality on small electronics / SMD parts. Before / After Sample photos of PCB with 0603 LEDs: Internal mounting 7 small rod magnets are used to snap the lens into the camera magnetically. The lens to be easily removed for operation…
What is it? Visit www.blamba.de yourself to find out. If you happen to have an old feature-phone with working cellular data, visit wap.blamba.de on it. Background Blåmba is a modern, open-source re-implementation of the popular commercial ringtone and multi-media providers for cellphones back in the early 2000s. If you weren’t around back then, many companies offered small little ringtones,…
Warning: While this project does work and has been tested against a number of devices, the firmware is very quick & dirty with hardcoded parameters and missing error handling. Use in production environments is discouraged. What is it? Old computers, machines and test equipment often expect printers to be directly connected via a parallel port / LPT / IEEE 1284. In the modern day, this is…
What is it? These mechanical adapter PCBs allow the use of PC104 and Vortex86DX X-ISA single board computers on an ISA backplane. Such adapters are available commercially for industrial use at extreme prices (100$+), for simple passive adapters. PC104 adapter Vortex86DX adapter
What is it? A USB-C sync and charging adapter for the Palm serial dock connector. Problems with other adapters A common problem with other adapters is that they often require a hardware RS-232 serial port, making use of an additional adapter with modern hardware necessary. There was also a USB-equipped docking station available but that one is very large, too. Also it has only USB-A so strictly…
What is it? Gigaset-Debug-Adapter can be used with many Gigaset DECT phone models to access the internal UART. It’s basically a 1.8V USB->UART converter, with switchable strapping logic and 3V step-down converter. The device fits into the battery tray and mechanically emulates 2 AAA batteries. The dialog-cr16c-uart-boot bootloader can be used to upload a stub to the phone through the boot…
What is it? This mechanical adapter allows older devices (like the popular apu2 SBCs) to use modern M.2 NVMe storage. Usage 2 adapters installed in a PC Engines apu2 with Samsung PM991 NVMe SSDs: M.2 adapters in an APU2"> Links Hardware : KiCAD design files
Your browser does not support the video tag. What is it? 3.5" floppy disks hold information by storing them magnetically on 80 different tracks (effectively circles) across the media. A stepper motor moves a read/write head across the media and can select which track is being accessed. In normal computer usage, the tracks are being formatted/modulated with modified frequency modulation (MFM) to…
Safety note The A/C is being powered by a ST VIPER12A switch mode supply. This type of supply is not mains-isolated, so all voltages (even the low voltages) are referenced to mains voltage. Don’t work on this device while plugged in without being aware of the implications of this! Every metal piece, every wire, every component inside can be at deadly voltage potentials against mains earth!…
What is it? Samsung / Commodore SQ-1000 electronic typewriters can be modified to work as a teletype terminal. They use a simple 8bit microcontroller to scan the keyboard matrix and do the printing itself. The keyboard was originally attached using a flat-flex connector directly to the mainboard. The connector was unsoldered and connected to an Arduino microcontroller, which emulates the keyboard…
What is it? SolarCamPi is an off-grid webcam solution, that can take a picture using a Raspberry Pi Camera or a USB webcam every 5 minutes and send the image over a long-distance WiFi link. Using a very specialised Linux image on the Raspberry Pis SD card, booting, taking a picture and sending it over WiFi can be done in under 15 seconds. This allows the Raspberry Pi to be powered off most of the…
What is it? A replacement LED backlight for the popular Palm IIIc handheld computers (“PDAs”) of the early 00s. The original CCFL backlight (high voltage fluorescent tubes in a portable device!) uses a lot of power for very little brightness. This mod can be used replace broken/worn out CCFL tubes in a Palm handheld. Modification PCBs Links Hardware : KiCAD design files
What is it? A small PCB, which can receive RS232 over IrDA/IrCOMM (for example from Palm PDAs, Nokia phones, old laptops) and relay it to a RS232 device. Modded ISDN terminal adapter This ELSA MicroLink ISDN terminal adapter was modified to include such a IrDA adapter PCB. It can now be used wirelessly from a Palm PDA to sync data without having to connect it to a PC.
Your browser does not support the video tag. Hardware Specs 1x STM32F7 taking care of power management, USB and display multiplexing 1x ESP32 Pico D4 providing a web interface to build and store animations 20x HC595 shift registers for row and column control 768x Tiny 1x1mm RGB LEDs arranged in 1.7mm pitch grid Features only 84mm wide and 29mm tall WLAN enabled 48x16 glorious RGB led pixels with…
PlutoSDR (or ADALM-PLUTO) is an inexpensive SDR (software-defined radio) platform by Analog Devices. It uses a Xilinx Zynq Z-7010 FPGA, which integrates an 32bit ARMv7 core together with the FPGA functionality. This 32bit ARMv7 CPU runs Linux and is normally (when used as an SDR via USB) just passing libiio messages to the host computer. The USB port on the PlutoSDR can also be used as a host/OTG…
What is it? At the Hacken Open Air 2021 (Gifhorn, Germany) event, this 5m by 3m large LED display was built. It consists of 50 individual LED strings with 50 WS2812 LEDs each (50x50 pixels). A central Raspberry Pi feeds 3 seperate STM32F722 via UART. These then generate the pixel data for the individual chains of LEDs. Each LED chain has it’s own 24V -> 5V buck regulator.
What is it? ATAPIMega is a hardware project which allows regular (P)ATA CD/DVD drives to be used as a standalone Audio-CD player. The PCB accepts (regulated!) 12V DC power via a 5.5mm/2.1mm barrel jack and outputs 12V/5V for the CD drive. The microcontroller is an ATmega2560 (Arduino Mega-compatible), chosen for 5V-I/O voltage and high pin-count (and bad availability of STM32’s in the…
What is it? fxIP is a port of uIP 1.0 to Casio fx-9750/fx-9860 calculators. It requires calculators with a SuperH SH4a CPU, needs quite a bit of SRAM. fxIP connects to IP networks via SLIP encapsulation over the 3-pin 2.5mm 5V serial port/UART. Webserver fxIP was used to serve a demo page to several thousands of visitors. The project was featured on Golem and Hacker News and actually survived the…
What is it? These PCBs contain eMMC storage ICs, which are electrically compatible with SD and microSD interfaces. They use a different protocol and (depending on the type of eMMC IC used) can be more reliable and faster. Many (but not all!) SD card slots/readers can also handle eMMC. These adapters can be used in devices like Raspberry Pis, APUs, etc. to provide stable eMMC storage through the SD…
What is it? ISA NE2000-compatible network card Using RTL8019 chipset, 10Base-T full duplex ethernet Can be configured via jumpers, EEPROM or full ISA PnP. Compatible with 8-bit XT machines. Optimized for automated assembly at JLC. Plug & Play Links Hardware & Drivers : KiCAD design files
What is it? Parallel ROMs (OTP-ROMs, EPROMs, EEPROMs, NOR flash, etc.) can be used as simple, programmable logic devices. They can be programmed to hold a lookup-table / bit stream, which will emulate logic functions (like 74-series logic) by responding to a certain pattern on the “input” (aka address lines) with a pre-calculated “output” (on the data lines).
Overview This is a build log of an IBM XT-compatible system called “ Micro 8088 ”, designed by Sergey Kiselev. micro8088 CPU card specifications: NEC V20 CPU (4.77 MHz, 7.16 MHz and 9.54 MHz CPU frequencies) Faraday FE2010A chipset 640 KiB RAM (+ XMS) PS/2 keyboard interface 8bit ISA interface Other ISA cards in the system:
What is it? This project allows the use of ISA extension cards on a modern computer over a USB interface. The main project goal was to learn about the ISA bus, not to build a polished product. USB limitations USB has inherent limits to the minimum latency, defined by the frame timing in the USB specification. This means that a USB 1.1 attached device will only ever be able to handle 1000 transfers…
What is it? This passive adapter PCB allows the use of HP FlexibleLOM extension cards (like 10/40 GbE network cards) in regular PCIe slots. FlexibleLOM extension cards are available used at very low prices (due to them not being PCIe compatible, despite using the same physical slot). Development photos For easier prototyping, a PCIe to 0.1" header PCB was designed:
What is it? This adapter board provides the required voltage level conversion, anode supply and filament bias voltages to run a Noritake MN12864K graphical vacuum fluorescent display. Bad Apple Links Breadboard adapter : KiCAD design files STM32F7-based controller : KiCAD design files
What is it? pata-gpio is a Linux kernel driver for GPIO bitbanged PATA (also known as ATA/ATAPI or IDE). Pin configuration can be set via device tree, the regular ATA framework is used. IDE Primary/Secondary device support is implemented.