hybridgroup.gobot/platforms/jetson/pwm_pin_test.go

package jetson

import (
	"errors"
	"testing"

	"gobot.io/x/gobot/gobottest"
	"gobot.io/x/gobot/sysfs"
)

var _ sysfs.PWMPinner = (*PWMPin)(nil)

func TestPwmPin(t *testing.T) {
	fs := sysfs.NewMockFilesystem([]string{
		"/sys/class/pwm/pwmchip0/export",
		"/sys/class/pwm/pwmchip0/unexport",
		"/sys/class/pwm/pwmchip0/pwm0/enable",
		"/sys/class/pwm/pwmchip0/pwm0/period",
		"/sys/class/pwm/pwmchip0/pwm0/duty_cycle",
		"/sys/class/pwm/pwmchip0/pwm2/enable",
		"/sys/class/pwm/pwmchip0/pwm2/period",
		"/sys/class/pwm/pwmchip0/pwm2/duty_cycle",
	})

	sysfs.SetFilesystem(fs)
	defer sysfs.SetFilesystem(&sysfs.NativeFilesystem{})

	pin, err := NewPWMPin("32")
	gobottest.Assert(t, pin.Export(), nil)
	gobottest.Assert(t, pin.Enable(true), nil)
	val, _ := pin.Polarity()
	gobottest.Assert(t, val, "normal")
	gobottest.Assert(t, pin.InvertPolarity(true), nil)
	val, _ = pin.Polarity()
	gobottest.Assert(t, val, "normal")

	period, err := pin.Period()
	gobottest.Assert(t, err, errors.New("Jetson PWM pin period not set"))
	gobottest.Assert(t, pin.SetDutyCycle(10000), errors.New("Jetson PWM pin period not set"))

	gobottest.Assert(t, pin.SetPeriod(20000000), nil)
	period, _ = pin.Period()
	gobottest.Assert(t, period, uint32(20000000))
	gobottest.Assert(t, pin.SetPeriod(10000000), errors.New("Cannot set the period of individual PWM pins on Jetson"))

	dc, _ := pin.DutyCycle()
	gobottest.Assert(t, dc, uint32(0))

	gobottest.Assert(t, pin.SetDutyCycle(10000), nil)
	dc, _ = pin.DutyCycle()
	gobottest.Assert(t, dc, uint32(10000))

	gobottest.Assert(t, pin.SetDutyCycle(999999999), errors.New("Duty cycle exceeds period."))
	dc, _ = pin.DutyCycle()
	gobottest.Assert(t, dc, uint32(10000))

	gobottest.Assert(t, pin.Unexport(), nil)
}