World's smallest Arc server

The frame below is being served was being served by the Arc language web server running on a SheevaPlug plug computer. (I've replaced the live connection with a screenshot, as I needed to use the SheevaPlug for something else.) Screenshot

The SheevaPlug

SheevaPlug in the wall The SheevaPlug is a compact, inexpensive ($99), low-power (5W), ARM-based Linux server built into a wall-plug. It's fairly powerful despite its size, with an Ethernet port, Flash storage, and a 1.2GHz processor. See plugcomputer.org for more information.

Marvell gave me a SheevaPlug and I thought it would be an interesting platform for experimenting with Arc as a web server. The SheevaPlug seems like a good platform for an always-running web server.

The picture shows the SheevaPlug plugged into the wall, with the Ethernet cable at the bottom. That's not a wall-wart power supply; that's the whole computer.

Since the plug runs Linux, I can just ssh into it and use it like any other Linux server. I installed mzscheme on the SheevaPlug (apt-get install mzscheme), downloaded the Arc language with wget, used iptables to map port 80 to port 8080, and so on. Dynamic DNS provides a DNS name for my SheevaPlug.

Arc

Arc is a new dialect of Lisp, designed by Paul Graham and Robert Morris. It's designed to be compact, flexible, and useful for exploratory programming.

The Arc language now (finally) runs on the current version of mzscheme (link). The ARM version of mzscheme 4.1.3 is easily installable on the SheevaPlug, making it straightforward to run Arc on the SheevaPlug.

The demo is a simple program using the Arc web server. It lets you vote on a set of choices and then graphs the result using a simple HTML/CSS graph. The Arc demo also serves its own source code here.

I'm using Arc on the SheevaPlug mostly to see if it works, since I've been using Arc for a while. For normal SheevaPlug use, you'd probably want to use Apache, PHP, Python, or another normal web server configuration; they all have ARM packages that you can simply install.

I'm just assuming this is the world's smallest Arc server; we'll see if anyone runs Arc on something smaller.

If the server is not working, either I shut it down to do something else or it crashed. Send me email and let me know. You can access the server without the iframe here.

I've also used a Python web server on the SheevaPlug, which is a more mainstream way to go than Arc. In that case, I connected an Arduino to the SheevaPlug, so my Arduino could be accessed over the web.

Admittedly, the demo is just a proof-of concept. The next step is to do something non-trivial with the SheevaPlug and Arc.

3 comments:

desNotes said...

Nice proof-of-concept. I have a SheevaPlug also and in the near future plan to incorporate it in my Digi XBee wireless network providing the web server for the system.

desNotes

finno said...

Neat! It's a shame that the SheevaPlug is only useful in US power sockets.

Ken Shirriff said...

Finno, apparently the SheevaPlug works in European power sockets too (details).The power prongs pop off and can be replaced with European prongs (or a power cord if you don't want to plug directly into the wall).