In [ ]:
import matplotlib.pyplot as plt
import numpy as np
%matplotlib inline
def saw(x):
return x % 50
x = np.arange(0, 200)
plt.plot(x, saw(x))
In [ ]:
import magma as m
m.set_mantle_target("ice40")
from loam.boards.icestick import IceStick
N = 8
icestick = IceStick()
icestick.Clock.on()
for i in range(N):
icestick.J3[i].output().on()
In [ ]:
import mantle
main = icestick.main()
# TODO: Define main
m.EndDefine()
In [ ]:
m.compile('build/sawtooth', main)
In [ ]:
%%bash
cd build
cat sawtooth.pcf
yosys -q -p 'synth_ice40 -top main -blif sawtooth.blif' sawtooth.v
arachne-pnr -q -d 1k -o sawtooth.txt -p sawtooth.pcf sawtooth.blif
icepack sawtooth.txt sawtooth.bin
iceprog sawtooth.bin
Wire up the GPIO pins to a logic analyzer to verify that the circuit produces the correct sawtooth waveform.
You can also use Saleae's export data feature to output a csv file. Replace our sample data with yours to check your results using matplotlib.
In [1]:
import csv
import magma as m
with open("data/saw-capture.csv") as saw_capture_csv:
csv_reader = csv.reader(saw_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]
In [7]:
import matplotlib.pyplot as plt
%matplotlib inline
plt.plot(timestamps[:500], values[:500], "-")
Out[7]: