Intel Edison generic calculator shield photo journal

[MarkHaysHarris777]

Greetings, I've placed my development board in a case (to protect it primarily, and secondarily to speed and ease the prototyping process). My tri-state voltage shifters came in the mails from adafruit today, so I'll be making a compare|contrast with pics. The voltage shifters are going to improve the product considerably, as well reduce the build complexity (not to mention keep most folks out of the woods in terms of these low voltage logic boards like the edison, or the due). Casing the edison mini breakout board was fairly straight-forward but required some modeling skills-- a large amount of plastic needed to be removed from the case; I used scalpels and a high speed dremmel tool. The casing included mounting header pins to the mini breakout board, providing a barrel connector for power, and exposing the LED view-ports and pinout expansion openings. Some hi-res pics, then compare|contrast with the voltage shifters:



The case measures 7.5cm x 5cm x 2.9cm. It basically has two tops, or two bottoms depending on your perspective. During testing as a server and software development board it sits on the bench pins down (lights up). When being used as a hardware development board it sits pins up to expose the expansion breakouts slot. I chose to NOT solder a barrel connector to the breakout board itself. Intel provides for this, but I chose to put the barrel connector in the case housing, running the power line internally to the two pin jumper J21. Now for the shifter compare|contrast, and some more hi-res pics:



The obvious difference here is the lack of reference resistors, and also a lack of pullup resistors, in the second pic. The second pic highlights the 8 channel tri-state voltage shifter from adafruit which Barry M recommended to me a couple of weeks ago. It not only provides tri-state logic (the 339 does not) but it also works across a wide range of voltages. All that is needed to 'program' the chip is to provide both the VccA and VccB reference voltages (from the source) in this case 1v8 from the edison, and 5v0 from my display system. The voltage shifter also comes with an output enable OE line, normally held HIGH. This line is beauty. Under program control if the line is pulled low then the 'port' is effectively closed... that is the shifter is quiesced (disabled), and the outputs are pulled low (plus, the shifter goes into a very low power saving mode). The production board may use the small surface mounted chip... or I may use the 74LVC245 (tri-state, works the same way) 20 pin standard package. The shifter from adafruit is nice for bread boarding, but they are pricey (almost nine bucks $9 US) I was impressed that header pins shipped with the board. There is no reason, however, if a person wanted to put the adafruit shifter in their project; it has a tiny form factor and is easy to solder to.

At this point, in my opinion, the edison is the board to beat... there are some issues with the RPi board, but I'm still looking at it. Its going to be very hard to beat the edison board for perks across the board, so to speak.

Cheers,
marcus