On Sun, Jul 19, 2009 at 4:59 PM, Jason Hsu wrote: > 'm part of the Data Acquisition subgroup of Project Phoenix, a group > working on an open source blood pressure monitor. > > I'm trying to figure out what surface-mount microcontrollers we could > use. =A0I need to figure out what our options are before I decide what > programmer to get. > > Page 2 in the following PPT presentation shows what kind of input the > microcontroller needs to process: > http://www.phoenix.tc-ieee.org/0001_Bibliography/2007-05-24%20EMB%20Prese= ntation/2-Carl-Sensors_20070520_Phoenix%20Sensor2.ppt > > Basically, there are two pulses from two sensors. =A0The systolic blood > pressure we're measuring is a function of the time difference between > the peaks of the two pulses. =A0The diastolic blood pressure we're > measuring is a function of the time difference between the troughs of > the two pulses. > > Does this application require a DSPIC, or would a regular > microcontroller suffice? =A0So far, my DSP background has been entirely > theoretical. =A0Whatever we use, the microcontroller must take samples > at a very high rate so that the exact timing of the peaks and troughs > is accurate. =A0A sample rate that is too low would make the timing of > the peaks and troughs very inaccurate. =A0I believe that this > application calls for a DSPIC due to the need to take and analyze data > from so many samples. =A0Am I correct, or am I way off base? > > If this application requires a DSPIC, are there any simple DSP > projects I could try to get some practice? =A0Again, I am new to using > DSP in a circuit. > I can't open .ppt on this computer (no microsoft stuff on it) but I think you are getting ahead of yourself. Get some sample data and develop the algorithm on your desktop PC first. Use Matlab or Octave. Then translate to C with fixed-point data to make sure the algorithm still works. Then use that code to determine how many IPS you need. Regards, Mark markrages@gmail -- = Mark Rages, Engineer Midwest Telecine LLC markrages@midwesttelecine.com -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist