| | 11 | Potential problems: The ultrasonic sensor transmits a burst of ultrasonic sound and then listens for the echo. The echo is received by a transducer that converts sound energy to electrical energy. The further away the target is, the weaker the received signal will be. To accurately measure longer distances, the sensor must be able to measure the very small voltages generated by the reflected signal and if the power supply to the sensor is fluctuating rapidly (we call that a noisy supply line) it is tough to do that (sort of like trying to hear someone whispering at a loud concert). You can reduce the noise on the power supply lines by adding a decoupling capacitor: a small capacitor placed between +5v and Gnd as close to the ultrasonic sensor as possible. For more information on power supply decoupling, see [DecoulingCapacitor here]. NOTE: you should use a non-polarized ceramic capacitor, however if you use an aluminum electrolytic capacitor (ask a mentor), you must observe the correct polarity, connecting the - lead to ground and the other lead to +5v...otherwise, the capacitor will turn into a firecracker. |
