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 ") 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!")