Parallax X-Band Circuit Disables COM port when positive lead is connected.

Other Hardware Sensors
1

Good Evening All,

I am attempting to attach my Parallax X-Band Motion Detector (Download - Parallax) to my Arduino Uno and what should be a very simple test has me spinning my wheels for hours today. I hope one of you can quickly identify what I am doing wrong. I scanned the forums and the web and could not find anything that indicated that I have this configured incorrectly. My IDE is running on Windows 7.

The Parallax board has 4 pins (EN, OUT, +5V, GND). We can forget about the first two for now. I connect the GND lead from the Parallax to one of the GND leads on the Uno directly below the 5V pin. I then connect the +5V lead of the Parallax to the 5V pin of the Uno. This is where the trouble begins. If I have a simple Hello World type sketch running with the Serial Monitor open, it stops running and my COM3 port goes away entirely.

One interesting thing to note is that when I connect the +5V lead to the Uno, the computer (windows laptop) makes a sound like a new USB device has been added.

For reference, even though, I am 100% sure this is not related, here is my parochial sketch of Hello World.

void setup() { Serial.begin(9600); }

void loop() {   Serial.println("hello world");  }

I must be doing something really stupid. I have a Vilros starter kit that comes with a standard type Breadboard. I've used this breadboard with Servos and LEDs with no problems at all.

Thanks for your advice!

2

In your loop() function, put a delay of 500 -1000 after serial print. You may be flooding the serial port. This can happen if you are sending faster than serial monitor con handle.

3

Just when I thought I did all the right searches, I found this link on the forum, http://forum.arduino.cc/index.php/topic,24574.0.html. When I changed the registry key shown below (from the article) my Com 3 port automatically started working properly.

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Parport\Parameters]
"DisableWarmPoll"=dword:00000001

It's interesting that this issue does not happen with all sketches in Windows 7. It only appeared when I tried to use the Parallax X-Band Motion Sensor.