Externally triggered ADC

Discussion in 'The Projects Forum' started by clockdoctor, Jun 29, 2011.

  1. clockdoctor

    Thread Starter New Member

    Jun 29, 2011

    I was wondering can anyone offer a little advice.

    I am trying to develop a system for sampling the mains electricity waveform at a rate of 12 kHz. In order for the data to be useful, it must be sampled at an exact time, disciplined by a GPS receiver.

    I can generate a 12 kHz waveform readily from a GPS receiver and PLL, but I am having difficulty sourcing an ADC that has an external trigger (as opposed to an external clock).

    More details on the specification I am trying to achieve are available here: http://openpmu.codeplex.com/wikipage?title=OpenPMU GPS Disciplined DAQ&referringTitle=Home

    Can anyone comment if they have built anything similar? I am considering using an ARM mbed cpu to manage packaging data from the ADC (SPI) into XML sent via UDP.

    All suggestions and comments are much appreciated. :)
  2. wayneh


    Sep 9, 2010
    I have no idea, but I've had good luck getting technical support from the LabJack people, on their forums. They might have some ideas, especially if their equipment could do what you seek.
  3. NLightNMe

    New Member

    Apr 20, 2011
    Rather than a stand alone ADC, have you looked into a microcontroller (uC) with an ADC? With a uC you should be able to setup one of the digital pins to trigger an interrupt and start an ADC conversion. Or, you could feed the 12kHz signal into a uC counter and have the counter generate interrupts at any divisor of the signal.