import matplotlib.pyplot as plt

sample_rate = 1000 # sample per second
frequency = 5      # Hz
duration = 1       # seconds

period = sample_rate / frequency # number of samples
print(f"The period: {period}")

time = []
voltage = []

sample = 0

while sample < sample_rate * duration:
    t = sample / sample_rate
    phase = sample % period
    
    if phase < period / 2:
        v = 1.0
    else:
        v = 0.0

    time.append(t)
    voltage.append(v)

    sample += 1 # this moves the while loop forward

plt.figure(figsize=(10,4))
plt.plot(time, voltage, '.-', markersize=3)
plt.xlabel("Time (S)")
plt.ylabel("Voltage (V)")
plt.title("Point-by-Point Square Wave")
plt.grid(True)
plt.ylim(-0.2, 1.2)
plt.show()