#Acq_IncClk.py

# This is a near-verbatim translation of the example program
# C:\Program Files\National Instruments\NI-DAQ\Examples\DAQmx ANSI C\Analog In\Measure Voltage\Acq-Int Clk\Acq-IntClk.c

import numpy
from pylab import *
from nidaqmx import *

class AnalogInDevice :
    def __init__(self, dll, parms) :
        # dll is the handle to the dll.  device is the "Dev1", etc..
        self.dll = dll
        # Define constants corresponding to values in  C:\Program Files\National Instruments\NI-DAQ\DAQmx ANSI C Dev\include\NIDAQmx.h
        self.Cfg_Default = int32(-1)
        self.Volts = 10348
        self.Rising = 10280
        self.FiniteSamps = 10178
        self.GroupByChannel = 0
        self.ChanForAllLines = 1
        self.RSE = 10083
        self.ContSamps = 10123
        self.GroupByScanNumber = 1

        # initialize variables
        self.data = numpy.zeros((parms.samples_raw,),dtype=numpy.float64)

    def PotentialChannel(self, task_handle, parms) :
        # Establish the potential channel
        self.dll.DAQmxCreateAIVoltageChan(task_handle, parms.channel,"",
                                   self.Cfg_Default, parms.min, parms.max, self.Volts, None) # or RSE (single-ended) instead of Cfg_Default?

    def ConfigureTiming(self, task_handle, parms) :
        self.dll.DAQmxCfgSampClkTiming(task_handle, parms.clock_source, parms.sample_rate,
                                       self.Rising, self.FiniteSamps, parms.samples)    # or ContSamps instead of FiniteSamps?

    def TakeData(self, task_handle, parms) :
        types=Types()
        read = types.read
        self.dll.DAQmxReadAnalogF64(task_handle, parms.samples_raw, parms.buffer_size,
                             self.GroupByChannel, self.data.ctypes.data,
                             parms.samples_raw, ctypes.byref(read),None)
        return read

class ADCParameters :
    def __init__(self, types, min, max, timeout, buffer_size, sample_rate, samples, channel, clock):
        # Use: ADCParameters(t, -10.0, 10.0, 10, 10000.0, 2000, 'Dev1/ai0', 'OnboardClock')
        self.min = types.float64(min)     #-10.0)
        self.max = types.float64(max)     # 10.0
        self.timeout = types.float64(timeout)     #10.0
        self.buffer_size = types.float64(buffer_size)      #10
        self.pointsToRead = buffer_size
        #self.pointsRead = types.uInt32()
        self.sample_rate = types.float64(sample_rate)     #10000.0)
        self.samples = types.uInt64(samples)      #2000)
        self.samples_raw=samples
        self.channel = ctypes.create_string_buffer(channel)     #'Dev1/ai0')
        self.clock_source = ctypes.create_string_buffer(clock)       #'OnboardClock')


def Simple() :
    dll, message = LoadDLL()
    if dll == 0 :
        print 'Library not loadable.  ' + message
        sys.exit()
    t = Types()
    task = CreateTask(dll, t, 0)    # Create task 0
    p = ADCParameters(t, -10.0, 10.0, 10, 100, 10000.0, 2000, 'Dev1/ai0', 'OnboardClock')    # types, min, max, timeout, buffer_size, sample_rate, samples, channel, clock
    a = AnalogInDevice(dll, p)     # Initialize the analog input device
    a.PotentialChannel(task, p)     # Open an analog input channel for the task
    a.ConfigureTiming(task, p)    # Configure the timing for taking data points on this channel for this task.
    StartTask(dll, task)                     # Begin the task
    data_points_taken = a.TakeData(task, p)   # Take some data
    print "Acquired %d points"%(data_points_taken.value)
    plot(a.data)
    show()
    EndTask(dll, task)
    ClearTask(dll, task)
    

#----------------------------------------------------------------------------------------------------------------------------------------------------

if __name__ == '__main__' :
        Simple()