I’m using the JSN-SR04T ultrasonic distance sensors to measure the height of water in holding tanks. I tested one outside of the system and the sensor worked flawlessly, but now that I have installed 6 of them and tried reading a value from any of them, they all give me the same result (~8.5in, or ~1160us). I have since tried uninstalling all but one to try to troubleshoot, but that only results in it reading a 0 distance, which has only added to my confusion.
This is what my set up looks like for the sensor hookup to the photon. I know it’s kind of hard to understand what’s going on so I’ll explain whats connected where.
Each sensor has PWR, GND, Echo and Trip pins. Each sensor’s PWR and GND pins are connected through a breadboard to a 5V supply that also powers the photon. The sensor boards light up when connected to power and like I said, I can get a reading from them, so I know the software side of things works, it’s just that the values I get don’t correspond to reality. Each Trig pin from the sensors is connected to an analog pin on the photon A0-A5 and each Echo pin is connected to a digital pin D0-D5.
I have tried unhooking 5 of the 6 sensors and then testing the remaining one by itself, but that has only resulted in a return value of 0. I’ve also tried powering them through the 3.3v and GND pins on the photon itself since some of the other sensors I have played around with in the past needed a direct connection to the photon when voltages needed to be measured to read values, but these sensors not only need 5V to work, they’re also not working through a fluctuating voltage, which makes me think that this is not the problem. The only other thing I can think of is that maybe having the sensor boards touching could be causing an issue, but again this seems like it would only be the case if voltage cross-talk would be a problem. I’m going to continue testing each sensor individually and see if I can crack the problem, but if anyone has any suggestions or any direct experience working with these sensors that could help me out, I would appreciate it.