Building a Better ybox

Saturday, October 20, 2007 by darco
Posted in , ,

original-ybox You remember the ybox, right? That do-it-yourself networked set-top box in an Altoid's tin?

Oh. Maybe not. Well, it was pretty cool.

There is a special place in my heart for the original ybox, as it is what finally got me into tinkering with microcontrollers. However, the more I've learned, the more things I can find wrong with it's current design:

  • It's expensive! The XPort component is $51 in single quantities!
  • The XPort shielding isn't properly grounded on the original PCB, so if you have stray VDD wire touch the XPort, you just fried a $51 part! (I speak from experience)
  • The PCB seems largely autorouted, with lots of vias and unnecessarily long traces for the video signal.
  • Did I mention it was expensive?

So I've set out to make a better and less expensive networked set-top box in an altoids tin. It should be around $40 cheaper to build. This is what the board is looking like:


UPDATE: The ybox2 has been built, and has it's own page! Check it out.

Here is a list of what's different:

  • Uses a Microchip ENC28J60 ethernet controller for network connectivity. The network stack will be implemented on the propeller.
  • Uses a tri-color LED (instead of the single LED of the original) for more informative unit status at a glance. (also more bling)
  • Has headers on almost all of the unused pins on the propeller, to facilitate tinkering.
  • Adds an extra pin to the prop-plug header for VDD (next to the VSS pin).
  • No vias, and the bottom copper is entirely groundplane. All signals are on the top copper layer, making it easier to see what is going on.
  • Integrated piezo-electric speaker for bells and whistles.
  • At least $40 cheaper!

I wanted to add PoE support as well, but after researching that a bit it seems that to do it right would increase the complexity of the device considerably—so I left that out for now.

I'm not sure when I'll send the design off to get fabricated, as I'm not entirely sure if this is going to be the final layout.

Thoughts and suggestions are welcome!