import math
import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline

def sine(x):
    return np.sin(2 * math.pi * x)

x = np.linspace(0., 1., num=256, endpoint=False)

plt.plot(x, sine(x))

import magma as m
m.set_mantle_target("ice40")

import mantle
from loam.boards.icestick import IceStick

N = 8

icestick = IceStick()
icestick.Clock.on()
for i in range(N):
    icestick.J3[i].output().on()

"""
Explanation: Sine Wave Generator
End of explanation
"""


main = icestick.main()

counter = mantle.Counter(32)
sawtooth = counter.O[8:8+8]

wavetable = 128 + 127 * sine(x)
wavetable = [int(x) for x in wavetable]

rom = mantle.Memory(height=256, width=16, rom=list(wavetable), readonly=True)

m.wire( rom(sawtooth)[0:8], main.J3 )
m.wire( 1, rom.RE )

m.EndCircuit()

"""
Explanation: To implement our sine wave generator, we'll use a counter to index into a ROM that is programmed to output the value of discrete points in the sine wave.
End of explanation
"""


m.compile('build/sin', main)

%%bash
cd build
cat sin.pcf
yosys -q -p 'synth_ice40 -top main -blif sin.blif' sin.v
arachne-pnr -q -d 1k -o sin.txt -p sin.pcf sin.blif 
icepack sin.txt sin.bin
iceprog sin.bin

"""
Explanation: Compile and test.
End of explanation
"""


import csv
import magma as m
with open("data/sine-capture.csv") as sine_capture_csv:
    csv_reader = csv.reader(sine_capture_csv)
    next(csv_reader, None)  # skip the headers
    rows = [row for row in csv_reader]
timestamps = [float(row[0]) for row in rows]
values = [m.bitutils.seq2int(tuple(int(x) for x in row[1:])) for row in rows]

"""
Explanation: We can wire up the GPIO pins to a logic analyzer to verify that our circuit produces the correct sine waveform.

We can also use Saleae's export data feature to output a csv file. We'll load this data into Python and plot the results.
End of explanation
"""


plt.plot(timestamps[:250], values[:250], "b.")

"""
Explanation: TODO: Why do we have this jitter? Logic analyzer is running at 25 MS/s, 3.3+ Volts for 1s
End of explanation
"""


