HC-SR04 Dummy Question

Other Hardware Sensors
1

Sooo...
i've connected my nano with the lcd/Keypad shield and an HC-SR04
Got my display working, using one of the buttons to start and end measuring, measure with the HC-SR04
and display the calculated distance as float on my lcd....

plugged into my computer the distance is no problem, but i want to use the prototype with a small usb power bank.
When is use the construction with the usb power bank the sensor only measures up to 44 cm... somethimes 47cm...
on my computer the limit is the usb-cable :wink:
but definitefly more than 47 cms..

Sooo... my question is: could it be that my power bank is causing this?
and what kind of power supply would you suggest?

2

could it be that my power bank is causing this?

Yes.

and what kind of power supply would you suggest?

One that allows the Nano to operate constantly at 5V. I don't know what type of power bank you're using but I guess that it is not supplying a constant enough voltage of at least 5V. If you measure the voltage while using the Arduino, what do you measure with a multimeter?

If you get more than 5V, post a complete wiring diagram of your setup and post your complete code.