Question: I'm working on a project where my arduino talks to another device that uses serial communication. I've connected my USB cable to a USB-to-serial adapter, so it can communicate with the device.

The problem I'm running into is powering the device: if I'm using the USB for serial, I can't use it for power. I have made sure that the device isn't turning on by putting 

```
pinMode(13, OUTPUT);
for (int i = 0; i < 10; i ++) {
    digitalWrite(13, HIGH);
    delay(1000);
    digitalWrite(13, LOW);
    delay(1000);
}

```

at the start of the `setup` function: if it works, it should start by blinking LED 13. 

I tried powering it with a 5V power supply through the power jack, next to the USB connector, but that didn't work. Is there something I'm missing? Do I need a different type of power supply?

Answer: 
Changing to double quotes with header files in the same folder worked for me.
The question is a bit unclear, however as far as I know, for the included libraries use: 

```
#include <SPI.h> 

```

So the `<` and `>` are used for common libraries which are in the C:\Program files...\Arduino folder 

And for specific (own made or sketch-depending) include files 

```
#include "MyFile.h"

```

should be used, which should be located in the same folder as the sketch file.