Repairing the hand

• Attached strain gauges to the bottom side.  Will start wiring on Monday.

Learning Electronics:

• I am about halfway through the book now.
• Multiplexer was the word I was looking for the other day when we were talking about the i2c bus.  I was surprised that the bus did not need a multiplexer in the diagrams I saw.  I think the reason a multiplexer is not needed is because there is a small one inside the i2c slave devices controller.
• Finished chapter on numbering systems, Binary Arithematic, and Boolean algebra.  This was mostly review of things I learned in COSC 101.  There are some techniques in the boolean algebra section which you can use to simplify the amount of comparisons needed to reach a desired result.  In electronics this means getting from A to B with less transistors.  In programming this could be useful in making the program run more efficiently.

Other Experimentation:

• Assembled another bridge to test the circuit board type strain gauges.
• Attached the second one to the test stick.  The glue we are using is made to work with this type of strain gauge and for whatever reason seemed to dry much fast while in contact with the insulator used.
• Soldering wire to the leads is a bit tricky but is a much less delicate process then trying to wrap the unpackaged strain gauges around the wire.
• Was worried that these strain gauges would be less sensitive but it seems that they are just as sensitive and that they play better with gain and offset adjustments better(more consistent results).
• Seems very durable.  I pulled on the wires harder then I would ever intentionally pull on them and they did not budge.  No need to put a think layer of epoxy on it,  only a small amount of glue would be needed to insulate the connection to prevent shorts.
• One side of the stick was already insulated the other was not.  I did not add any insulation to the side that didn’t have it and it seems fine.
• Since we don’t have many of these stain gauges,  I still plan to use the standard type for this prototype.  However, if I have to repair this one again, as well as future pr0totypes,  I would like to use these prepackaged strain gauges due to their ease of application, increased durability, and greater aesthetic value(no big glob of epoxy needed).  There are many sites that sell versions of these but the ones we have are really nice because they have big leads that are easy to solder to.  If you can remember where you got them from tell me, otherwise I will try to find something equivalent.
• This test stick will be used for experiments with the tactile/audio feedback system once I get the amplifiers and usb-i2c device sometime next week.

I think Clift forgot about me…. 😦  Hopefully he will come to the lunch Christina planned next Tuesday.  Its no big deal, gives me some time to read this book so I can ask more complicated questions.