I'm having some issues with my Arduino Due and connecting an external power supply and USB connection. To give the context to my project I'm building an ultrasound circuit and there are connections between the circuit and Arduino, as seen in the diagram.
I insert the USB to the Arduino and upload the code. Then I plug in the external power supply and Arduino seems to disconnect every time I insert the external supply. Then I turn on the circuit supply and nothing really happens because I'm disconnected from the COM5.
Another issue is when the in insert both the USB and external supply before turning on the circuit supply, The circuit supply is warning me the current is going over the maximum limit of 1A. ( My circuit supply is two DC bench power supplies set to 9V/1A to get +9/GND/-9). I decided to test the pin voltage at specific pins.
Pin 5: -3.14V
Pin A7 : 3.14V
I'm not really sure what's happening but I've tried resetting the Arduino and changing external supplies but the same thing keeps happening. Also, another thing to add is when the circuit supply warns me of the overload of current I take out the wire connecting to Pin 5 and re-insert it back in and the current level goes back to normal ( around 0.10-0.12A).
Sender Circuit Diagram:
Sender Hardware wirings:
Receiver circuit diagram:
Receiver wirings (red wire to the far right is the connection to pin A7 on Arduino)