# template tile for Lab #7, Task #5
import numpy
import waveforms as w

# parameters that control the encoding
sample_rate = 1e6
bits_per_second = 30000
samples_per_bit = int(sample_rate/bits_per_second)

# convert message bits into samples, then use samples
# to modulate the amplitude of sinusoidal carrier
def am_transmit(bits,samples_per_bit,fc):
    pass # your code here

# receive amplitude-modulated transmission:
def am_receive(samples,fc,samples_per_bit):
    pass # your code here

if __name__ == '__main__':
    message_size = 32

    # a random binary message
    message = numpy.random.randint(2,size=message_size)

    # run transmitter
    fc = 125e3  # carrier frequency
    xmit_out = am_transmit(message,samples_per_bit,fc)

    ##################################################
    ## ADDED FOR TASK #5: try different transmission delays
    ##################################################
    for delay in xrange(8):
        print "%d-sample delay:" % delay
        delayed_xmit_out = xmit_out.delay(nsamples=delay)

        # run receiver
        received = am_receive(delayed_xmit_out,fc,samples_per_bit)

        # report results
        print '    message: ',message
        print '    received:',received
        if not numpy.array_equal(message,received):
            print '    => differences'
        else:
            print '    => message received okay'