Subject: General Tech | April 3, 2013 - 05:43 PM | Tim Verry
Tagged: wireless display, Raspberry Pi, paperwhite, mobile, kindle, e-ink
The Raspberry Pi makes for a cheap and low power media PC, file server, or desktop but the lack of a display means that it is not very portable. Recently a hack was posted online by Max Ogden that enables the Rasbperry Pi to be used on the go by pairing it with an Amazon Kindle and its e-ink display. His wireless display setup was actually based on a previous hack that allowed the Pi to be paired with the 3rd-generation Kindle. Ogden's hack takes things a step further by supporting the latest Paperwhite versions as well as no longer requirig a wired connnection between the display and the Raspberry Pi.
By loading the Raspberry Pi with Raspian Linux and adding a terminal emulator to the Kindle, the Kindle connects to the Pi over an SSH session where the Pi console and any keyboard input can be seen on the Kindle's e-ink display. The hardware needed to make the setup work includes a Wi-Fi hotspot, a Wi-Fi USB NIC, The Raspberry Pi, a supported Kindle, and a battery pack with enough juice to power everything. A wired or wireless keyboard and Wi-Fi dongle can be added to the Raspberry Pi Model B, bu Model A users will need to add a USB hub as the $25 model only supports a single USB port on the device itself.
Max Ogden shows off his new portable battery-powered Raspberry Pi with wireless e-ink display.
There are some limitations to this setup. One is a bit of latency between typing and seeing the characters appear on the screen due to the low refresh rate inherent in e-ink displays and the wireless connection. Ogden estimates that this delay is around 200ms, and is noticeably but bearable while typing. The other major limitation is that the display can currently only be used to display the Pi console, and not the GUI of Raspian. For writing code or articles, you could get by with a command-line text editor like nano or vi--at the very least it would be a distraction-free writing environment as you could not procrastinate and browse Reddit or watch videos even if you wanted to (heh).
If you are interested in setting up your own wireless Raspberry Pi display, you should check out Ogdens blog for a list of recommended hardware as well as Rod Vagg's tutorial on configuring the Kindle Paperwhite with the correct software.
This is one of the more-useful Raspberry Pi hacks that I've seen so far. Hopefully, a future hack will come along that will also allow one of these e-ink devices to display the GUI desktop environment and not just the terminal.
Subject: General Tech | July 28, 2012 - 06:49 AM | Tim Verry
Tagged: wireless display, wifi alliance, widi, tegra 3, nvidia, miracast
NVIDIA has announced its support for a new wireless display technology called Miracast. The creation of the Wi-Fi Alliance and its partners, Miracast is a wireless technology that allows direct connections (sans router) between a Wi-Fi enabled device and a Wi-Fi enabled television set. It is a much more open standard than the proprietary technologies like Intel’s WiDi. Devices will require certification much like other Wi-Fi routers and wireless adapters. The Miracast standard certification program is set to launch soon with the standard’s specifications published sometime in August. Any device manufacturer will be able to use the standard and go through certification, though whether or not we will see the high adoption rate that many are hoping for remains to be seen.
Interestingly, it looks as though NVIDIA is going to be one of the first adopters of the Miracast standard by integrating it into its Tegra 3-powered mobile devices. Using the Tegra 3 “4+1”-core System on a Chip, NVIDIA plans to use the chip to encode the audio and video information and pass it to the Wi-Fi stack where it is passed, via Wi-Fi, to the wireless display. The company wants you to be able to use its mobile tablets and smartphones as a controller to be able to play media and even games on the big screen. According to a recent blog post, NVIDIA is “actively working with our OEM partners and Miracast receiver vendors to bring this technology to market.” The company has further promised more specific updates once the Wi-Fi Alliance finalizes the specification.
Miracast sounds good, as an open wireless display standard, but it is going to face some stiff competition from proprietary technologies. Apple’s Air Play, AMD's Wireless Display, Intel’s WiDi, and software like Android Transporter are all currently in use, and it is unlikely that those companies will forego the invested technology for an open standard. Miracast can certainly still work as a standard for all other devices, but that raises some questions. Mainly, whether or not a number of alternative devices using Miracast will be a large enough interest to compel display makers to support it. Hence my surprise when NVIDIA pledged its support, as it has the potential to be a big player in helping Miracast succeed. I'll remain skeptically optimistic on this one, but I'm curious what you think. Do you think that it will be successful as a wireless display standard?
You can read more about Miracast in this whitepaper (PDF).