gobot.io/x/gobot/v2@v2.1.0/examples/nanopi_led_brightness.go (about)

     1  //go:build example
     2  // +build example
     3  
     4  //
     5  // Do not build by default.
     6  
     7  package main
     8  
     9  import (
    10  	"fmt"
    11  	"time"
    12  
    13  	"gobot.io/x/gobot/v2"
    14  	"gobot.io/x/gobot/v2/drivers/gpio"
    15  	"gobot.io/x/gobot/v2/platforms/nanopi"
    16  )
    17  
    18  // Wiring
    19  // PWR  NanoPi: 1, 17 (+3.3V, VCC); 2, 4 (+5V, VDD); 6, 9, 14, 20 (GND)
    20  // GPIO NanoPi: the fourth header pin at inner USB side, count from USB side, is the PWM output
    21  // LED: the PWM output is NOT able to drive a 20mA LED with full brightness, so a custom driver or low current LED is needed
    22  // Expected behavior: the LED fades in and out
    23  func main() {
    24  	r := nanopi.NewNeoAdaptor()
    25  	led := gpio.NewLedDriver(r, "PWM")
    26  
    27  	work := func() {
    28  		brightness := uint8(0)
    29  		fadeAmount := uint8(15)
    30  
    31  		gobot.Every(100*time.Millisecond, func() {
    32  			if err := led.Brightness(brightness); err != nil {
    33  				fmt.Println(err)
    34  			}
    35  			brightness = brightness + fadeAmount
    36  			if brightness == 0 || brightness == 255 {
    37  				fadeAmount = -fadeAmount
    38  			}
    39  		})
    40  	}
    41  
    42  	robot := gobot.NewRobot("pwmBot",
    43  		[]gobot.Connection{r},
    44  		[]gobot.Device{led},
    45  		work,
    46  	)
    47  
    48  	robot.Start()
    49  }