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import os
import sys
import periphery
from .test import ptest, pokay, passert, AssertRaises
if sys.version_info[0] == 3:
raw_input = input
pwm_chip = None
pwm_channel = None
def test_arguments():
ptest()
# Invalid open types
with AssertRaises("invalid open types", TypeError):
periphery.PWM("foo", 0)
with AssertRaises("invalid open types", TypeError):
periphery.PWM(0, "foo")
def test_open_close():
ptest()
# Open non-existent PWM chip
with AssertRaises("non-existent PWM chip", LookupError):
periphery.PWM(9999, pwm_channel)
# Open non-existent PWM channel
with AssertRaises("non-existent PWM channel", periphery.PWMError):
periphery.PWM(pwm_chip, 9999)
# Open legitimate PWM chip/channel
pwm = periphery.PWM(pwm_chip, pwm_channel)
passert("property chip", pwm.chip == pwm_chip)
passert("property channel", pwm.channel == pwm_channel)
# Initialize period and duty cycle
pwm.period = 5e-3
pwm.duty_cycle = 0
# Set period, check period, check period_ns, check frequency
pwm.period = 1e-3
passert("period is correct", abs(pwm.period - 1e-3) < 1e-4)
passert("period_ns is correct", abs(pwm.period_ns - 1000000) < 1e5)
passert("frequency is correct", abs(pwm.frequency - 1000) < 100)
pwm.period = 5e-4
passert("period is correct", abs(pwm.period - 5e-4) < 1e-5)
passert("period_ns is correct", abs(pwm.period_ns - 500000) < 1e4)
passert("frequency is correct", abs(pwm.frequency - 2000) < 100)
# Set frequency, check frequency, check period, check period_ns
pwm.frequency = 1000
passert("frequency is correct", abs(pwm.frequency - 1000) < 100)
passert("period is correct", abs(pwm.period - 1e-3) < 1e-4)
passert("period_ns is correct", abs(pwm.period_ns - 1000000) < 1e5)
pwm.frequency = 2000
passert("frequency is correct", abs(pwm.frequency - 2000) < 100)
passert("period is correct", abs(pwm.period - 5e-4) < 1e-5)
passert("period_ns is correct", abs(pwm.period_ns - 500000) < 1e4)
# Set period_ns, check period_ns, check period, check frequency
pwm.period_ns = 1000000
passert("period_ns is correct", abs(pwm.period_ns - 1000000) < 1e5)
passert("period is correct", abs(pwm.period - 1e-3) < 1e-4)
passert("frequency is correct", abs(pwm.frequency - 1000) < 100)
pwm.period_ns = 500000
passert("period_ns is correct", abs(pwm.period_ns - 500000) < 1e4)
passert("period is correct", abs(pwm.period - 5e-4) < 1e-5)
passert("frequency is correct", abs(pwm.frequency - 2000) < 100)
pwm.period_ns = 1000000
# Set duty cycle, check duty cycle, check duty_cycle_ns
pwm.duty_cycle = 0.25
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.25) < 1e-3)
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 250000) < 1e4)
pwm.duty_cycle = 0.50
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.50) < 1e-3)
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 500000) < 1e4)
pwm.duty_cycle = 0.75
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.75) < 1e-3)
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 750000) < 1e4)
# Set duty_cycle_ns, check duty_cycle_ns, check duty_cycle
pwm.duty_cycle_ns = 250000
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 250000) < 1e4)
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.25) < 1e-3)
pwm.duty_cycle_ns = 500000
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 500000) < 1e4)
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.50) < 1e-3)
pwm.duty_cycle_ns = 750000
passert("duty_cycle_ns is correct", abs(pwm.duty_cycle_ns - 750000) < 1e4)
passert("duty_cycle is correct", abs(pwm.duty_cycle - 0.75) < 1e-3)
# Set polarity, check polarity
pwm.polarity = "normal"
passert("polarity is normal", pwm.polarity == "normal")
pwm.polarity = "inversed"
passert("polarity is inversed", pwm.polarity == "inversed")
# Set enabled, check enabled
pwm.enabled = True
passert("pwm is enabled", pwm.enabled == True)
pwm.enabled = False
passert("pwm is disabled", pwm.enabled == False)
# Use enable()/disable(), check enabled
pwm.enable()
passert("pwm is enabled", pwm.enabled == True)
pwm.disable()
passert("pwm is disabled", pwm.enabled == False)
# Set invalid polarity
with AssertRaises("set invalid polarity", ValueError):
pwm.polarity = "foo"
pwm.close()
def test_loopback():
ptest()
def test_interactive():
ptest()
pwm = periphery.PWM(pwm_chip, pwm_channel)
print("Starting interactive test. Get out your oscilloscope, buddy!")
raw_input("Press enter to continue...")
# Set initial parameters and enable PWM
pwm.duty_cycle = 0.0
pwm.frequency = 1e3
pwm.polarity = "normal"
pwm.enabled = True
# Check tostring
print("PWM description: {}".format(str(pwm)))
passert("interactive success", raw_input("PWM description looks ok? y/n ") == "y")
# Set 1 kHz frequency, 0.25 duty cycle
pwm.frequency = 1e3
pwm.duty_cycle = 0.25
passert("interactive success", raw_input("Frequency is 1 kHz, duty cycle is 25%? y/n ") == "y")
# Set 1 kHz frequency, 0.50 duty cycle
pwm.frequency = 1e3
pwm.duty_cycle = 0.50
passert("interactive success", raw_input("Frequency is 1 kHz, duty cycle is 50%? y/n ") == "y")
# Set 2 kHz frequency, 0.25 duty cycle
pwm.frequency = 2e3
pwm.duty_cycle = 0.25
passert("interactive success", raw_input("Frequency is 2 kHz, duty cycle is 25%? y/n ") == "y")
# Set 2 kHz frequency, 0.50 duty cycle
pwm.frequency = 2e3
pwm.duty_cycle = 0.50
passert("interactive success", raw_input("Frequency is 2 kHz, duty cycle is 50%? y/n ") == "y")
pwm.duty_cycle = 0.0
pwm.enabled = False
pwm.close()
if __name__ == "__main__":
if os.environ.get("CI") == "true":
test_arguments()
sys.exit(0)
if len(sys.argv) < 3:
print("Usage: python -m tests.test_pwm <PWM chip> <PWM channel>")
print("")
print("[1/4] Arguments test: No requirements.")
print("[2/4] Open/close test: PWM channel should be real.")
print("[3/4] Loopback test: No test.")
print("[4/4] Interactive test: PWM channel should be observed with an oscilloscope or logic analyzer.")
print("")
print("Hint: for Raspberry Pi 3, enable PWM0 and PWM1 with:")
print(" $ echo \"dtoverlay=pwm-2chan,pin=18,func=2,pin2=13,func2=4\" | sudo tee -a /boot/config.txt")
print(" $ sudo reboot")
print("Monitor GPIO 18 (header pin 12), and run this test with:")
print(" python -m tests.test_pwm 0 0")
print("or, monitor GPIO 13 (header pin 33), and run this test with:")
print(" python -m tests.test_pwm 0 1")
print("")
sys.exit(1)
pwm_chip = int(sys.argv[1])
pwm_channel = int(sys.argv[2])
test_arguments()
pokay("Arguments test passed.")
test_open_close()
pokay("Open/close test passed.")
test_loopback()
pokay("Loopback test passed.")
test_interactive()
pokay("Interactive test passed.")
pokay("All tests passed!")
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