Newbie struggling with Adafruit lesson 3: RGB LED HELP!
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Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by mountainman13 on Thu Jan 10, 2013 2:41 pm

I am getting mixed partial patterns from my RGB LED. I cut and pasted the sketch from the lesson and that seems to work fine. I have everything wired as per ADAfruit lesson 3 and get a light green and light yellow blinking LED. When I remove the wire that goes to ground I get a blinking pattern of red, violet, blue. What am I missing here? Thanks.
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by adafruit_support_bill on Thu Jan 10, 2013 4:43 pm

Is this the tutorial you are using?: http://www.ladyada.net/learn/arduino/lesson3.html
That is written for 3 individual leds. To wire an RGB led, we need to know if it is a common cathode or common anode led. Did you purchase it from Adafruit?
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by mountainman13 on Thu Jan 10, 2013 11:21 pm

I am using the Arduino lesson # 3 not the tutorial. I did not purchase my kit from Adafruit, I got it as a gift for Christmas. I have been using the lessons and tutorials from Adafruit as they seem to be the best on the web. I don't know if it is a common cathode or anode so I tried switching it. When I tried switching the wire from ground to +5 it changed from the green and yellow to red, violet, and blue after I removed the wire and after plugging it into 5 it stayed red, violet, and blue.
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by adafruit_support_bill on Fri Jan 11, 2013 6:12 am

In the updated series you are using, the diagram is for a Common Cathode. Most of the ones we have in the store are common anode. It sounds like the pin you are connecting to GND or +5v may not be the common pin. Usually the common pin is slightly longer than the other 3.
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by mountainman13 on Fri Jan 11, 2013 3:25 pm

When I use the slightly longer pin I get no light at all. Any thoughts on what I must be doing wrong? Thanks.
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by adafruit_support_bill on Sat Jan 12, 2013 5:56 am

When I use the slightly longer pin I get no light at all

When you use it how? Using just the longer pin and one of the other pins, connect it as if it were a single LED. If it lights up with the long pin connected to 5v, it is a common anode led. If it lights up with it connected to GND, it is a common cathode.
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Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!

by Syn7 on Thu Jan 17, 2013 12:59 am

Take the long pin and hook it up to 0V, -, or ground, and put any of the other pins on +, or 5V. If it doesn't light up any color, switch em. If it does light up on either choice, leave the long pin alone and try the other pins to see the other two colors. If you have 5V or + on the long pin, you have Common Anode. If you have 0V on the long pin you have Common Cathode. Knowing the difference is important for how you set up your breadboard. Don't forget to use the resistor.

Figure that part out then you can move on to how to wire it up.
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