I added a link to possible sources for as many parts as I could.  However, there were a few things I scrounged from local surplus electronics stores and couldn’t easily find a good equivalent online.  I’m not expecting everyone to copy my design exactly (not everyone has a woodworking shop at their disposal), so use these numbers as a rough estimate only.

If you shop around you should be able to beat the listed prices on many items, so I see this as sort of a worst case scenario.

To flash the wireless router and create a minimal radio (with no user interface), you will need:

• Asus WL-520gU wireless router – currently $34.99 with MiR
• SYBA SD-CM-UAUD USB Stereo Audio Adapter – $7.99
• FTDI USB TTL-232 3.3V serial adapter cable – $20
• 0.1″ Break-away Header Strip – $2.50

Total: $65.48

To make the LCD display and tuner interface, you’ll also need:

• USBtinyISP AVR programmer – $22
• 16×2 Character LCD (5V) – $13.95
• ATmega168 microcontroller – $4.11
• 28-pin socket – $1.50
  
• 16MHz crystal – $1.50
• 2 x 22pF capacitors – $0.25 ea.
• Contrast trimpot, 1k (or similar) – ~$0.75
• Tuner potentiometer, 10k – $1.40
• Reset microswitch – $0.35
• Serial connector (cut an old CD-ROM audio cable in half) – $0
  
• Protoboard – $5
• Some hookup wire - $0
  
• 0.1uF bypass cap and a few resistors (10Ohm and 1K) - around $1 at any decent electronics store

Total: $52.06

(This is on the high end, the interface can certainly be built for less by using scrounged/surplus components.)

To make the finished radio, add:

• Volume and tune knobs – ~$2 @ HSC
• Cool tuner knob – $8.55
• 5V/12V power supply brick – $10 @ Weird Stuff
• 5-pin mini-DIN power connector – ~$3 @ HSC
• Power switch – ~$1 @ HSC
• Cheap set of PC speakers (gutted for the speakers and amplifier) – $5 @ Weird Stuff

Total: $29.55

Oh yeah, and I almost forgot…

• An awesome friend named Tony with a full woodworking shop in his garage who will make you a killer wooden enclosure for free – $priceless

Grand total (excluding the box) – $147.09

If you take out the cost of the development tools, namely the FTDI cable and the USBtinyISP, the total comes out to $105 (without the box).

By scrounging materials and using parts from your junkbox you should be able to reduce that figure even more, but obviously the grand total hinges on what kind of enclosure you use.  Not everyone has a friend with serious woodworking skills willing to donate time and materials, but use this as an excuse to get creative.

I wanted a box that showcased the time and effort that I spent on the electronics inside, but that doesn’t mean an old boombox from the Salvation Army couldn’t work just as well.

When I first started this project, my goal was to keep the total parts cost under $100.  On paper, it looks like I came pretty close to that, thanks to the donated box and excluding the reusable development tools like the FTDI cable and AVR programmer.  To be honest, I probably spent twice that amount on spare power supplies, extra knobs, a second router to bring to NOTACON, and a bunch of other stuff that I didn’t end up using in the final project.  But I’m pretty ok with that.  I think this just highlights the fact that:

If you just want a Wifi Radio, it will always be cheaper to buy one off the shelf. But if you make your own, it will be infinitely more rewarding.

It certainly has been for me. 

Yesterday, Sparkfun had a solder paste stencil class at their HQ in Boulder, CO.

@esawdust was there and took lots of great photos and notes about the class:

Sparkfun Stencil and Solder Paste Class | PCB, Solder Paste | sawdust.see-do.org

Wish I could have been there, it looks like everyone had a great time!