import os
import time
import math
import u3
import datetime

SAMPLE_RATE_SECONDS = 30

# MAX_REQUESTS is the number of packets to be read.
MAX_REQUESTS = 1
# SCAN_FREQUENCY is the scan frequency of stream mode in Hz
SCAN_FREQUENCY = 2000


def main():
    daq = u3.U3()
    daq.getCalibrationData()

    # Set FIO0-FIO3 and FIO6 to Analog
    daq.configIO(FIOAnalog=0x4F)

    #writeFile(logFileName, "Configuring U3-HV stream\r\n")
    daq.streamConfig(NumChannels=5, PChannels=[0, 1, 2, 3, 6], NChannels=[32, 32, 32, 31, 31], Resolution=3, ScanFrequency=SCAN_FREQUENCY)

    while(1):
        try:
            daq.streamStart()
        except:
            # A previous stream could have been running. Stop it and try again.
            daq.streamStop()
            daq.streamStart()

        dataCount = 0
        for s in daq.streamData():
            if s is not None:

                if dataCount >= MAX_REQUESTS:
                    break
                print("\r\nHave data.")
                if s["errors"] != 0:
                    print("Errors counted: %s" %
                        (s["errors"]))
                    cnt = 0
                    # Display errors
                    for err in s['result'][11::64]:
                        errNum = ord(err)
                        if errNum != 0:
                            # Error detected in this packet
                            print("  Packet %s, error %s" % (cnt, errNum))
                        cnt+=1

                if s["numPackets"] != daq.packetsPerRequest:
                    print("----- UNDERFLOW : %s" % 
                        (s["numPackets"]))

                if s["missed"] != 0:
                    print("+++ Missed %s" % s["missed"])

                dataCount += 1

            else:
                print("\r\nNo data")

        daq.streamStop()
        
main()