Where to buy highest quality HCSR04? All mine stopped working!

Hi guys. Recently, I just started back up a project and tried hooking up four of my SainSmart HCSR04's that I got from amazon a while back and none of them would turn on the board's LED with the simple HCSR04 sketch, unless I touched the sensor. Then I tried setting the distance a lot further and they finally worked but not very well. So, I figured, it must be my sensors went bad or something. I live in a pretty humid place, so I thought it could be that. I ordered five new sensors from another website and none of those worked either, same issue. I extended the range on my program and then those still wouldn't work. What gives? I tried it with two different boards, so I'm not sure what to think. Does anyone have a place they'd recommend I could buy a really high quality HCSR04? Thanks!

It sounds like you have a code or wiring problem.

Ian_McElrath: got from amazon a while back

Did they work then, though, with the same wiring and code as you're using now? I'm asking since your headline says they "stopped working" implying that they worked before.

Hi, Something IS unusual here...

Use the code and setup on THIS PAGE

I have sold thousands of the garden variety HS-SR04 in kits and had only 1 or 2 bad...

Let us know what you find...

Let us know what you find...

No Answer. Does that mean Problem Solved???

There definitly are differences in quality. For example I have a bulk of sensors that works fine on arduino uno r3 if the uno (and so the sensors) gets voltage via usb. When connecting 9V via arduino power jack, the sensors quit working after a short time. Curious: You can wake them up for a short time by lightly “knocking” the sensor, but soon they fall asleep again.
Measured the voltage in both stages: 4.4V when connected via USB, 4.9V when connected via arduino voltage regulator. So I put a diode between arduino voltage and Vcc of sensor et voila: All worked fine again.
But as I didn’t want to change 24 PCBs, I ordered a new bulk like those I had before. The new ones work like a charm as they should with unchanged regulator power from the uno.

Only thing I can say about the sensor board is: Those who work only with limited Vcc have the Type “HC-SR04” more in the middle of the board and have only two holes in diagonal edges. The ones that work without complains have four holes in all four edges and the typo is directly under the oscillator.

@Maxpilot. What frequency are the X-tals ?

I ask because I have both 4MHz and 8MHz.. The 4MHz has the problem with 'high voltage'

Cannot tell, there is no print on them and I've no equipment here to measure.

Anyway, thanks for info!