I am having issues with a HC-SR04 Range Sensor once disconnected from USB power. My set up is:
A photon on the sparkfun battery shield with the HC-SR04 Range Sensor and a 3.7V 6Ah/22.2Wh Lipo battery.
It works fine when the photon is connected to USB. I have an event that fires every second and writes the distance measured by the range sensor to the cloud. When I run it off usb using the lipo and solar panel the sensor goes dead. It returns zeros. I know it has to do with the 5v sensor and the photon’s power output. Is there a way to get this to work using a booster, LIPO with more Voltage or a 3.3V Range Sensor???