Friday, September 2, 2011

Bread Board Working

I spent the last few days playing with getting a functioning set of electronics.  In the picture on this post, you can see two chips.  On the left is the Avago ADNS-7550 optical mouse sensor.  On the right is a Teensy 2.0 microprocessor development board.  I coded a firmware set for the Teensy using the Arduino development environment.  The two chips communicate via Serial Peripheral Interface ("SPI") and seem to get along pretty well at this point.

The ADNS-7550 optical sensor is more of a prototyping stand-in at this point.  Eventually, I plan to upgrade the sensor to the best optics I can get.  I asked Philips to send me a few Twin-Eye PLN-2032 sensor samples to work with, but once my contact there heard I wasn't part of a major manufacturer and planning a huge roll-out, I never heard back from him.  Since they don't offer their chips through normal distributors (like Mouser and DigiKey to name a few), I cannot buy them.  Oh well.  Avago also makes a nice ADNS-9500 that is about as good, maybe even better than the one Philips has.  Unfortuantely, I can't buy that ADNS-9500 in anything less than 1,000 piece lots.  Since I can buy the ADNS-7550 one at a time it will stand-in while I develop the proto-type and work through the bugs.  It works much the same as the big brother.  Once the bugs are out and things are working well I can look at what it will take to get a better resolution chip under the hood and possibly some extra funding...

The Teensy board I bought a couple of weeks ago has undergone minor surgery to convert it from 5 volt to 3.3 volt.  This is required so that the SPI signals are at the right voltage levels. 


  1. You can buy ADNS-9500 in a lot of 10 (5) pieces

  2. Yes, indeed they are available today. At the time of this post, there were none in stock with any US distributors. I was getting ready to order some of the ADNS-9500 from DigiKey yesterday, but now I see that the ADNS-9800 is released from Avago. It appears to be almost exactly the same as the ADNS-9500 with just a higher CPI capability. I'm awaiting a response from Avago regarding the ADNS-9800 before I order any more chips. They seem to be available at random times, so you have to get them while they are available it seems, then they will go out-of-stock again.