Increasing voltage output

I am using the arduino UNO with a memsic accelerometer. As of right now, I have a program to turn on a led when the accelerometer is tilted past a certain point. The output voltage to the led needs to be 9v. I think I am getting about 5v to the led. How can I raise this voltage to 9v? I was thinking about using a transistor 3904. Also when the accelerometer is tilted past a certain point, I need for the led to come on and stay on until a reset or clear button is hit. Any suggestions on if I should use a latch, flip flop, or whatever? Also please provide the chip number.

Well, the 1st thing you'll need is a source for 9V. After that, switching it shouldn't be a big problem. But it would sure help to know exactly what LED you're using.

Why consider a flip-flop or other "chip"? You have a microcontroller (so use it!) (: If the accelerometer crosses a threshold value then you assert digitalWrite a pin and it'll stay on:

void loop accel_read() If accel_read > threshold, LED = on If clearbutton = true, LED = off

9v for an LED? Something seems off here.

Ok thanks I will use that code. I don’t know why but I didnt think of that.

Also I have an 9v source. The led has a built in resistor and can handle a max of 16v. I just want to power it with 9v. It is a red led assembly from radio shack 276-0270.

Radio shack has the led here: http://www.radioshack.com/product/index.jsp?productId=2062568

Hollojj: Ok thanks I will use that code. I don't know why but I didnt think of that.

Also I have an 9v source. The led has a built in resistor and can handle a max of 16v. I just want to power it with 9v. It is a red led assembly from radio shack 276-0270.

I see no mention of a built-in resistor or of voltage range allowed in their "tech spec" such as they are. ;)

http://www.radioshack.com/product/index.jsp?productId=2062568#tabsetBasic

Maybe it's printed on the packaging?

Would be way easier to start with the right parts from the beginning. Just get a normal LED, add your own resistor, run directly from Arduino.