After yesterday's success of using potentiometers on a breadboard to simulate the x and y-axes of an accelerometer, we took the next step and finally implemented the control system with an accelerometer. We used a piece of 2-inch foam to make a bridging plate in the hamster ball. This allowed us to strap the accelerometer, Xbee radio, and necessary circuit boards down rigidly. Once that was all done we tried driving the RC boat prototype around (see video below). It was very fun, and once we fine-tune some motor mapping, the control system should be very intuitive. 

Other accomplishments today include:

• The implementation of the 10 LEDs (actually 5 LEDs with red and green leads) using two daisy-chained shift registers (74HC595) which are controlled using the SPI (SSP on PIC) communication protocol. 
  
• Getting SPI communication to work between the AVC Xbee PIC and the main AVC PIC, as well as between the Security Controller PIC and the main PIC. 

After yesterday's check off (having the CVC xbee talk to the ACV xbee), we decided to take it one step further, having the CVC actually send motor commands over to the ACV. For our drive train functions, since we plan on having one "orb" to control everything with an accelerometer, luck would have it that our motor mapping functions from 218b fit very nicely  with this control system (http://218b.weebly.com/software.html). For this prototype we used one potentiometer to act as the forward and backwards command (a la y-axis of accelerometer) and another potentiometer as the turning (x-axis of accelerometer). It was a bit tricky to control the boat, but the hamster ball should work a lot better! 

Please see the videos below to see our boat on its RC maiden voyage (unfortunately we did not have champagne). This was a quick and dirty prototype (lots of duct tape), but we definitely got a feel for how easy the boat is to control, and it also showed us that some tweaking needs to be done in the motor mapping. 

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David went out and bought a cheap RC boat at Fry's.  We drove it around the Halo fountain today, in and out of the falls and over the lights, until the battery (we think / we hope) gave up on us.