Thanks to the worldwide proliferation of smartphones, tiny high-resolution displays are common and cheap. Interfacing these displays with anything besides a phone has been a problem. [twl] has a board that does just that, converting HDMI to something these displays can understand, and providing a framebuffer so these displays can be written to through small microcontrollers.
[twl] is using a rather large FPGA to handle all the conversion from HDMI to the DSI the display understands. He’s using an Xilinx Spartan-6-SLX9, one of the most hobbyist friendly devices that is able to be hand soldered. Also on the board is a little bit of SDRAM for a framebuffer, HDMI input, and a power supply for the LCD and its backlight.
On the things [twl] has in his ‘to-do’ list, porting Doom to run on a cellphone display is obviously right at the top. He also wants to test the drawing commands for the Arduino side of his board, allowing any board with the suffix ~’ino to paint graphics and text on small, cheap, high-resolution displays. That’s a capability that just doesn’t exist with products twice [twl]’s projected BOM, and we can’t wait to see what he comes up with.
You can check out the demo video of [twl]’s board displaying the output of a Raspberry Pi below. If you look very closely, you’ll notice the boot/default screen for the display adapter is the Hackaday Jolly Wrencher.
Continue reading “Using Cell Phone Screens with any HDMI Interface”
The Broadcom SOC in the Raspberry Pi is actually surprisingly powerful, it turns out. It’s actually capable of driving a VGA monitor through the GPIO pins using a handful of resistors.
[Gert van Loo], Raspberry Pi chip architect, wizard, and creator of a number of interesting expansion boards showed off a VGA adapter for the new B+ model at the recent Raspberry Pi Jam in Cambridge this week. Apparently, there is a parallel interface on the SoC that can be used to drive VGA with hardware using a resistor ladder DAC. That’s native VGA at 1080p at 60 fps in addition to HDMI for the Raspberry Pi. Only the new Model B+ has enough pins to do this, but it’s an intriguing little board.
The prospect of having two displays for a Raspberry Pi is very interesting, and the remaining four GPIOs available mean a touch screen could be added to one display, effectively making a gigantic Nintendo DS. Of course there are more practical problems a dual display Raspi solves, like driving a projector for the current crop of DSP/resin 3D printers, while still allowing for a usable interface during a print.
The VGA expansion board, “is likely to have issues with EMC,” which means this probably won’t be a product. Getting a PCB made and soldering SMD resistors isn’t that hard, though, and we’ll post an update when the board files are released.
Thanks [Uhrheber] for sending this one in.
[Tomasz] tipped us about the well documented MIPI DSI Display Shield / HDMI Adapter he put on hackaday.io. The Display Serial Interface (DSI) is a high speed packet-based interface for delivering video data to recent LCD/OLED displays. It uses several differential data lanes which frequencies may reach 1 GHz depending on the resolution and frame rate required.
The board explained in the above diagram therefore allows any HDMI content to be played on the DSI-enabled scrap displays you may have lying around. It includes a 32MB DDR memory which serves as a frame buffer, so your “slow” Arduino platform may have enough time to upload the picture you want to display.
The CP2103 does the USB to UART conversion, allowing your computer to configure the display adapter internal settings. The platform is based around the XC6SLX9 Spartan-6 FPGA and all the source code may be downloaded from the official GitHub repository, along with the schematics and gerbers. After the break we’ve embedded a demonstration video in which a Raspi drives an iPhone 4 LCD.
Continue reading “A MIPI DSI Display Shield/HDMI Adapter”
There’s a number of devices out there that extend HDMI over IP. You connect a video source to the transmitter, a display to the receiver, and link the two with a CAT5/5e/6 cable. These cables are much cheaper than HDMI cables, and can run longer distances.
[Daniel] didn’t care about extending HDMI, instead he wanted a low cost HDMI input for his PC. Capture cards are a bit expensive, so he decided to reverse engineer an IP HDMI extender.
After connecting a DVD player and TV, he fired up Wireshark and started sniffing the packets. The device was using IP multicast on two ports. One of these ports had a high bitrate, and contained JPEG headers. It looked like the video stream was raw MJPEG data.
The next step was to write a listener that could sniff the packets and spit the data into a JPEG file. After dealing with some quirks, JPEG images could be saved from the remote device. Some more code was needed to have the computer initiate the streaming, and to extract audio from the second port.
In the end, video capture with the low cost device was possible. [Daniel] also provided a bonus teardown of the device in his writeup.
Want to get a hold of a gaming controller attachment for iOS at a rock bottom price? [Dark GOD] learned that Amazon is closing out the Gameloft DUO Gamer hardware for $6 because the hardware is no longer supported by the operating system. He shows how to make it work using a Cydia app. [Thanks ProMan]
[Frank Zhao] had a cheap HDMI switch which had problems with a sagging power rail. His solution was to hack in a USB port to inject some power.
This security hack uses an Arduino with LCD screen to display a QR code. Scan it with an Android device and you no longer need keys! Here’s the code repo and a demo video.
It’s interesting to see how many places the WS28xx pixels are popping up. Here’s a crowdfunding campaign that uses a matrix of the pixels as a portable gaming display. Look somewhat familiar? We’ve seen [Retro Brad’s] earlier hardware (made to play Super Pixel Bros.) that used an LED module instead. This is probably a lot easier to drive since it uses serial data instead of multiplexing.
Next is some robot building inspiration. [IronJungle] has been hard at work building a rover that uses compass bearings for navigation.
We liked seeing a drop-in replacment uC for Ikea Dioder projects, but if you need more power under the hood, take command of those colored lights with a Raspberry Pi.
Those lucky enough to have access to a laser cutter will find this Inkscape extension for living hinges useful.
Finally, POTUS threw down the gauntlet, encouraging everyone to learn how to program by pointing them toward the Hour of Code program. We’ve long thought that everyone should have some level of coding education. Do you agree with us? Of course, getting something like this into schools is a monumental challenge, so it’s nice to see extra-curricular offerings. We also believe that Hackerspaces are among the best driving forces for getting kids a tech education. [via Adafruit]
Casemodders extraordinaire [Downing] and [Hailrazer] are known for their fabulous builds that put just about every gaming console into a portable hand-held format. Everything from a Game Cube to N64s and a Sega Genesis have been conquered by the two, and for the last year they’ve been putting their heads together to make the best solution to portabalizing console gaming forever. It’s called the Cross Plane, and puts just about everything with an HDMI connection in the palm of your hand.
The build began as one of [Downing]’s more ambitious projects. He imagined a system that could play nearly every retro game on a small handheld device. After finishing this build, he set up a Kickstarter and called up his friend [Hailrazer] to get some feedback. Just hours before the Kickstarter launched, [Hailrazer] suggested making a device for modern consoles. [Downing]’s pride and joy was scrapped, but out of its ashes arose the Cross Plane.
Inside the Cross Plane is a wireless HDMI receiver and a 7″ 720p display. This, along with a few buttons and analog controls, allow the Cross Plane to serve as a remote display and controller for an XBox 360, Playstation 3, and even a PC, for all that retro emulator goodness.
It’s a really, really cool project, and since the dream of an open Wii U controller seem to have died, we’re thinking this could be a great controller for an FPV quadcopter or other remotely operated vehicle.
It may seem confusing that you’re looking at a Raspberry Pi when this hack is about an Ambilight clone system that doesn’t need a computer. The point here is that this system works no matter what your video source is, where many projects in the past have required the video to be playing from a computer.
This hack follows in the same path of the ARM based custom job we was almost a month ago. Just like that project you use an HDMI splitter to gain access to the feed going to your television. The split signal is fed into an HDMI to composite video adapter. The composite signal is captured by a USB video encoder. The GPIO header drives a strip of addressable RGB LEDs. The whole thing is powered as one using a bit of cable hacking.
It’s slightly convoluted. But all of the components are easy to source and relatively cheap. The one caveat is that it works best if you are already using a hardware HDMI source selector instead of the one build into your TV. That way there is just one HDMI cable going to the television, and this can siphon off of that feed.
Continue reading “No computer Ambilight clone uses a computer”