mruby/c 3.3 Standard I/O class support
Temperature Sensor: http://wiki.seeedstudio.com/Grove-Temperature_Sensor_V1.2/

sensor = ADC.new(19)
temp = 0
while true
  param = sensor.read
  param = (ADC.max / param)-1
  temp = 1.0/(Math.log(param)/4275+1/298.15)-273.15
  puts("temp:" + temp.to_s)
  sleep(1)
end
LED brightness control using a volume knob
Volume: https://www.switch-science.com/catalog/805/

volume = ADC.new(19)
led1 = PWM.new(0)
led1.frequency( 440 )
while true
  param = volume.read
  # adc value Γ— 100% Γ· maximum adc value (3.3V)
  param = (param * 100 / ADC.max).to_i
  led1.duty(param)
end
Joystick: https://www.switch-science.com/catalog/884/

x = ADC.new(19)
y = ADC.new(20)
while true
  puts("x:#{x.read} / y:#{y.read}")
  sleep_ms(300)
end