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# given the cmdline arg, turns the byte sequencies into a list of frequencies, and vice versa
# 1875 1924 +24, -25, range/2, 1, flipping new info 2 sending or not
import numpy as np
import pyaudio
import threading
def calculate_send_frequencies(start_freq, freq_range, bytes_per_transmit):
bits_to_send = 8 * bytes_per_transmit + 2 # 8 bits per byte, 2 bits for flags
freq_interval = freq_range / (bits_to_send + 1) # +1 to not include endpoints of range
freq_list = []
for i in range(bits_to_send):
f = int(start_freq + (i + 1) * freq_interval)
freq_list.append(f)
print(freq_list)
return freq_list
def frequencies_to_bytes(frequencies, expected_freqs):
# get the interval between frequencies, so we can clamp the range around them
freq_interval = expected_freqs[1] - expected_freqs[0]
plus_minus = freq_interval // 2
byte_list = ['0'] * len(expected_freqs)
for freq in frequencies:
for i in range(len(expected_freqs)):
# clamp the range around the frequency to the frequency
if expected_freqs[i] - plus_minus <= freq < expected_freqs[i] + plus_minus:
byte_list[i] = '1'
return byte_list
def play_data(data, start_freq, freq_step, bytes_per_transmit, p):
freq_list = calculate_send_frequencies(start_freq, freq_step, bytes_per_transmit)
for byte in data:
print(byte)
samples = None
for i, bit in enumerate(byte):
if bit == '1':
print(freq_list[i])
s = .125 * np.sin(2 * np.pi * np.arange(44100 * 10.0) * freq_list[i] / 44100)
if samples is None:
samples = s
else:
samples = np.add(samples, s)
if samples is not None:
print(samples)
stream = p.open(format=pyaudio.paFloat32, channels=1, rate=44100, output=True)
stream.write(samples.astype(np.float32).tobytes())
stream.stop_stream()
stream.close()
def receive_string(binary):
binary_string = ''.join(binary)
try:
print(chr(int(binary_string, 2)))
except ValueError:
print("Error: Invalid binary data")
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