Hi @Josh1977, welcome to the forum!
This is usually caused by having the RX and TX wires the wrong way around, or from the serial baud-rate being incorrect between the Arduino and the Ping device. Can you confirm which Ping1D firmware version you’re using? It’s possible our guide and/or code are outdated - I’ve asked internally and am trying to find out what the latest information should be.
In this recent thread I connected successfully to our latest firmware (
Ping-v3.28_auto) by changing the baud rate from 9600 to 115200 (e.g. change from
pingSerial.begin(115200)), which you may wish to try. Otherwise you should be able to roll back your firmware to
Ping-v3.27_9600 using PingViewer (as specified in the guide you linked to), after which the example code should work as-is assuming your wires are connected to the correct ports.