the Sociable Pint

The very first prototype of the circuit.

The original 3D CAD design of the original module casing.

In order to test the capabilities of the sensors and wireless network, I experimented with few basic versions of the final circuit.

After I was satisfied with the preliminary testing and circuit design, I sent out the circuit board to be printed.

This is what the circuit looked like after I soldered on all of the components. Because I have to cram so many components underneath a little pint glass, I settled on a 3 tier design.

The completed circuit securely fitted together.

The first three glasses.

I have submitted my first iteration of my circuit board design to BatchPCB for printing. Hopefully they will arrive any day now. At this point I am making 3 glasses. This will enable me to test the basic software functionality of the glasses.

It is my hope to have 12 glasses functional by the beginning of May but this completely depends on what grants I can get.

I recalculated the cost of each pint glass module and almost crapped my pants. After significantly reducing the cost of each glass, I am back up to about $250 per glass module. If I am able to produce a large amount of glasses at a time the cost will be reduced to under $100 per glass. It’s not like any individual component of the glass is that expensive. The problem is that I have many inexpensive components that add up. Add shipping, setup fees, and taxes, and I have a little financial hurdle on my hands.

Fortunately, I have left myself room in the circuit board to swap in and out the more expensive components for more inexpensive ones, so my next wave of glasses will be cheaper in price. I can solder on an ADXL330 chip instead of using the Sparkfun ADXL breakout board. I can leave out the Arduino Mini Pro module and manually solder the ATMEGA168 chip and the necessary components. These modifications will be difficult to complete and will take time (and a better soldering tip than what I have), but they will also reduce the component cost by $35 per glass. But with that being said, I really need to start making some design sacrifices.

At this time I just want to build the first iterations of glasses, complete the programming, and test them before I make any changes. I checked and rechecked my circuit board design a dozen times before I submitted it to be printed, but I am still worried about things not working perfectly. For one, I can’t properly test the effectiveness of the force sensor and the conductive film on the glass until they are completely built. Also I still am nervous about the current load of my DC-to-DC step up component. Anyway, even though this process has been painfully slow, I finally feel that I am making some real progress.

MESH NETWORK IS NOW FUNCTIONAL!!

ALL MODULES CAN COMMUNICATE WITH ANY OTHER MODULE WITHIN SIGNAL RANGE!!

RSSI IS WORKING IN ALL MODULES TO REVEAL (approximate) PROXIMITY OF CLOSEST MODULE!!

YAY!!

(finally)

(onto the next problem)

Here is my in-progress schematic of the circuit that will be packed underneath the glass:

click on the image for an expanded view.