#!/usr/bin/env python
"""
================================================
ABElectronics Expander Pi | DAC sine wave generator demo

Requires python smbus to be installed
For Python 2 install with: sudo apt-get install python-smbus
For Python 3 install with: sudo apt-get install python3-smbus

run with: python demo_dacsinewave.py
================================================

this demo uses the set_dac_raw method to generate a sine wave from a
predefined set of values
"""
from __future__ import absolute_import, division, print_function, \
                                                    unicode_literals

try:
    import ExpanderPi
except ImportError:
    print("Failed to import ExpanderPi from python system path")
    print("Importing from parent folder instead")
    try:
        import sys
        sys.path.append('..')
        import ExpanderPi
    except ImportError:
        raise ImportError(
            "Failed to import library from parent folder")


def main():
    '''
    Main program function
    '''
    dac = ExpanderPi.DAC(1)

    sinewave_array = \
        [2048, 2073, 2098, 2123, 2148, 2174, 2199, 2224,
         2249, 2274, 2299, 2324, 2349, 2373, 2398, 2423,
         2448, 2472, 2497, 2521, 2546, 2570, 2594, 2618,
         2643, 2667, 2690, 2714, 2738, 2762, 2785, 2808,
         2832, 2855, 2878, 2901, 2924, 2946, 2969, 2991,
         3013, 3036, 3057, 3079, 3101, 3122, 3144, 3165,
         3186, 3207, 3227, 3248, 3268, 3288, 3308, 3328,
         3347, 3367, 3386, 3405, 3423, 3442, 3460, 3478,
         3496, 3514, 3531, 3548, 3565, 3582, 3599, 3615,
         3631, 3647, 3663, 3678, 3693, 3708, 3722, 3737,
         3751, 3765, 3778, 3792, 3805, 3817, 3830, 3842,
         3854, 3866, 3877, 3888, 3899, 3910, 3920, 3930,
         3940, 3950, 3959, 3968, 3976, 3985, 3993, 4000,
         4008, 4015, 4022, 4028, 4035, 4041, 4046, 4052,
         4057, 4061, 4066, 4070, 4074, 4077, 4081, 4084,
         4086, 4088, 4090, 4092, 4094, 4095, 4095, 4095,
         4095, 4095, 4095, 4095, 4094, 4092, 4090, 4088,
         4086, 4084, 4081, 4077, 4074, 4070, 4066, 4061,
         4057, 4052, 4046, 4041, 4035, 4028, 4022, 4015,
         4008, 4000, 3993, 3985, 3976, 3968, 3959, 3950,
         3940, 3930, 3920, 3910, 3899, 3888, 3877, 3866,
         3854, 3842, 3830, 3817, 3805, 3792, 3778, 3765,
         3751, 3737, 3722, 3708, 3693, 3678, 3663, 3647,
         3631, 3615, 3599, 3582, 3565, 3548, 3531, 3514,
         3496, 3478, 3460, 3442, 3423, 3405, 3386, 3367,
         3347, 3328, 3308, 3288, 3268, 3248, 3227, 3207,
         3186, 3165, 3144, 3122, 3101, 3079, 3057, 3036,
         3013, 2991, 2969, 2946, 2924, 2901, 2878, 2855,
         2832, 2808, 2785, 2762, 2738, 2714, 2690, 2667,
         2643, 2618, 2594, 2570, 2546, 2521, 2497, 2472,
         2448, 2423, 2398, 2373, 2349, 2324, 2299, 2274,
         2249, 2224, 2199, 2174, 2148, 2123, 2098, 2073,
         2048, 2023, 1998, 1973, 1948, 1922, 1897, 1872,
         1847, 1822, 1797, 1772, 1747, 1723, 1698, 1673,
         1648, 1624, 1599, 1575, 1550, 1526, 1502, 1478,
         1453, 1429, 1406, 1382, 1358, 1334, 1311, 1288,
         1264, 1241, 1218, 1195, 1172, 1150, 1127, 1105,
         1083, 1060, 1039, 1017, 995, 974, 952, 931,
         910, 889, 869, 848, 828, 808, 788, 768,
         749, 729, 710, 691, 673, 654, 636, 618,
         600, 582, 565, 548, 531, 514, 497, 481,
         465, 449, 433, 418, 403, 388, 374, 359,
         345, 331, 318, 304, 291, 279, 266, 254,
         242, 230, 219, 208, 197, 186, 176, 166,
         156, 146, 137, 128, 120, 111, 103, 96,
         88, 81, 74, 68, 61, 55, 50, 44,
         39, 35, 30, 26, 22, 19, 15, 12,
         10, 8, 6, 4, 2, 1, 1, 0,
         0, 0, 1, 1, 2, 4, 6, 8,
         10, 12, 15, 19, 22, 26, 30, 35,
         39, 44, 50, 55, 61, 68, 74, 81,
         88, 96, 103, 111, 120, 128, 137, 146,
         156, 166, 176, 186, 197, 208, 219, 230,
         242, 254, 266, 279, 291, 304, 318, 331,
         345, 359, 374, 388, 403, 418, 433, 449,
         465, 481, 497, 514, 531, 548, 565, 582,
         600, 618, 636, 654, 673, 691, 710, 729,
         749, 768, 788, 808, 828, 848, 869, 889,
         910, 931, 952, 974, 995, 1017, 1039, 1060,
         1083, 1105, 1127, 1150, 1172, 1195, 1218, 1241,
         1264, 1288, 1311, 1334, 1358, 1382, 1406, 1429,
         1453, 1478, 1502, 1526, 1550, 1575, 1599, 1624,
         1648, 1673, 1698, 1723, 1747, 1772, 1797, 1822,
         1847, 1872, 1897, 1922, 1948, 1973, 1998, 2023]

    while True:
        for val in sinewave_array:
            dac.set_dac_raw(1, val)

if __name__ == "__main__":
    main()