hello_usb.nim

import picostdlib/[gpio]
import picostdlib

stdioInitAll() #is necessary for initializzate usb

const led1 = 25.Gpio; led1.init(); led1.setDir(Out) #enable a led on board try
var charX: char #create a char variable (getCharwithTimeOut return a char!!)
sleep (600)

while true:
  charX = getCharWithTimeOut(300)

  if charX  != '\255' :
    print("Char put -> " & charX & '\n')
    if charX == '1': #turn on led if recive 1 (char)
      led1.put(High)
    elif charX == '0': #turn off led if recive 0 (char)
      led1.put(Low)
    else: #blink a led in other case!
      for _ in 0..3:
        led1.put(High)
        sleep(300)
        led1.put(Low)
        sleep(100)

#use line termination for this example = none!!