Ultrasonic sensor

<iframe width="450" height="260" style="border: 1px solid #cccccc;" src="https://thingspeak.com/channels/1786665/widgets/489241"></iframe>

<iframe width="450" height="260" style="border: 1px solid #cccccc;" src="https://thingspeak.com/channels/1786665/widgets/489242"></iframe>

<iframe width="450" height="260" style="border: 1px solid #cccccc;" src="https://thingspeak.com/channels/1786665/widgets/489248"></iframe>