Archive for June, 2011

Dream Plug

Monday, June 27th, 2011 by hartmans

As part of trying to help with Freedom Box, I gained access to a Dream Plug The Dream Plug is one of the leading possible platforms for Freedom Box.

Computationally it’s sexy for a low-power device. There’s a 1200 mhz arm with 512m of RAM. As a platform to enable people to create novel applications, it’s great. It has multiple USB ports, two ethernets, a built-in 802.11B/G access point, bluetooth, audio, ESATA, Micro SD and full-sized SD. So, whether you application needs storage, networking, audio, or some interesting side device, you’re covered. With the optional JTAG adapter it’s even fairly friendly to developers: there are options for recovering from most failures and full console access. If you’re looking at a reference platform that’s still nominally embedded, but that allows you to play around thinking about what your application could do, this is a great option.

However, especially for Freedom Box, it’s important to remember that the reference board a developer wants is not the same as a cost-reduced product on which to actually deploy something for people to buy. The Dream Plug is wrong for every actual deployment I’ve imagined. First, it’s huge. If you happen to have free power plugs on your wall with lots of space above and below them, it might be an option. If however, you’re like everyone I know and have power strips, constrained spacing, etc, then the industrial engineering will disappoint at every turn. I was hoping for something that kind of looked like an Apple Airport Express. It’s significantly larger than that in every dimension. Also, the plug is oriented the wrong way for minimizing the fraction of the power strip it takes up. The power supply part of the device can be detached, although even that is way too huge for a power strip, and the cable between the power supply and the computer is fairly short. You can reconfigure the device without its plug nature: running a cord from a normal power outlet to the power supply. But then if you have to detach the power supply for heat management reasons, you get a cord from the outlet to the power supply and another cord from the supply to the device. Add a few USB or ESATA devices and the octopus of cables begins to resemble some arcane mechanism. (So far, no elder gods have appeared though.)

The other issue is that you almost never want all the functionality. You pay for the bluetooth, audio and ESATA in terms of cost, heat and space regardless of whether you use them. I don’t have a lot of applications that really take advantage of the full array of hardware.

The firmware update mechanism is decidedly not targeted at end-users. The version I obtained had a hacked copy of Debian lenny. No mechanism was provided for replacing the image in a safe manner that did not potentially require the optional highly-non-end-user-compatible JTAG board if something got interrupted. You could either unscrew the device and get to the micro SD card containing the image, or run software to replace the image from within Debian lenny. It’s possible to configure the boot loader to run an update image off USB or SD until that succeeds, but doing that is also a non-end-user operation.

In conclusion, the name is perfect. This is exactly what hackers need to dream about the power of small computers everywhere. However we must not forget that there’s a step required to turn dreams into reality. Just as with any fully proprietary product, Freedom Box will require cost reduction steps, semi-custom boards and actual OEMs to truly be usable. The claim in the previous sentence that the Freedom Box may have proprietary elements is disquieting to some. I think we can put together a software stack that is free with the possible exception of some device firmware. However, my suspicion is that anyone who turns that into a fully realized end-user product will add proprietary elements. I suspect some of the results of the cost reduction process such as resulting semi-custom boards will be proprietary. In many cases though, I suspect some proprietary software elements will be introduced.