Embedded system conception

Discussion in 'General Electronics Chat' started by lavoie23, Aug 13, 2009.

  1. lavoie23

    Thread Starter New Member

    Aug 13, 2009
    Hi everyone,
    First post! I have a crucial decision to take regarding the design of an embedded computer. The system itself is a portable medical device used in pneumology. At this time, there is already a fully functionnal prototype. However, for the next versions, the embedded computer must be changed and re-designed.

    The beast: A Rabbitcore RCM3900 (http://www.rabbit.com/products/rcm3900/)

    The system integrates:
    - Oxygen valve, RS-232
    - O2 sensor, RS-232
    - EtCO2 sensor, RS-232 or TTL
    - LCD screen, 20x4 char
    - SDCard Interface
    - USB and Bluetooth interface (communication with an extern computer)

    The principal contraints regarding the conception/choice of an embedded computer:
    - Low power consumption (it's a portable device)
    - Acceptable design complexity (hardware and software)

    I don't have a very long experience in electronic design, and I really need help on this one! Your ideas would be very appreciated!
  2. StayatHomeElectronics

    AAC Fanatic!

    Sep 25, 2008
    What is the main reason that you need/want to switch away from the current design?

    Why was the Rabbitcore chosen for the prototype?
  3. lavoie23

    Thread Starter New Member

    Aug 13, 2009
    The main reason why the rabbitcore has been chosen is by its simplicity. What's happening now is that the main program cannot be larger than it is currently (it's taking all the memory available). Consequently, we have trouble expanding it. Also, we are making a lot of calculations onboard, enough to see the limitations of the rabbit... In other word, I'm seeking something that could be a little more powerfull. Finally, even if this reason is not crucial, there are some feature that we really don't need (ex: Ethernet port), and others that we would need (ex: ADC converter).

    I made some research on some microcontrollers that I could probably use. The problem with a lot of them is that I need at least 4-5 independant serial interfaces (two for the sensors, one for the valve, one for the extern communication, and possibly one another for a SDCard interface).

    Thank you for your help!
  4. Papabravo


    Feb 24, 2006
    I do this kind of stuff for a living, and I'll be happy to help for a suitable inducement.