Post date: Feb 26, 2010 10:44:09 PM
First, I tested the 8mz 3.3v version of arduino board to determine whether it is fast enough to run the current program code. The 16 MHz version of the arduino can run the program code at 1 kHz speed. I expected the 8Hz arduino will run the program code at 500 Hz. the experiment showed that it indeed can run at 500 Hz.
Second, I try to send the sample data from PC to arduino. I ran into couple for problems. First, I found out that serial bus can only send 1 byte at a time. That means the maximum number can be received by arduino is 255. To overcome that problem, I wrote a simple protocol that allowed PC to read in one number of data from file, and then chop the data into two bytes by doing division of 256. Then send out each byte of data. Then when arduino received every 2 byte, it will combine those two bytes together and create an Int value.
I also set up the testing circuit for testing sample data. Now we have the hardware environment for testing collected data.
I did a sample hardware testing by feeding two sets of data we collected form ADD patient to the arduino. One set of data contains reading motion. During this testing, there were no warning and alarms got set off.
The second set of data contains none reading motion, during the testing, the “no moving” warning set off twice and didn't pick up other motions.
The conclusion of study indicates that our code is able to accurately detecting reading motion, but does not detect non-reading motion accurately enough. We will continue to refine our code and change threshold in the code to find the optimum detection method.
For the next week activity, I plan to review the PCB board design wit team members. I also will test the arduino circuit design to see if our power switch design works for our purpose.
I will also work with other team member to test, discuss, and conclude a communication protocol between PC and the microcontroller.