I am using the 15_Sensors_Example (https://code.google.com/p/arduino-new-ping/wiki/15_Sensors_Example) from NewPing library by @teckel and slightly modified it for 12 sensors. I have the sensors hooked up to a mega + Yun Shield. The first sensor always reports a 0, or rather "no ping".
The way i fixed it temporarily is I added a fake sensor to the beginning of the object array and when i go to upload the data, I just ignore that first sensor.
However, I would like to figure out what could be causing this. Power? Timing?
Also, the issue does not happen when i remove the Yun Shield and just have the Mega 2560 print to Serial.
Any paths i could take? Any potential things i could test?