Thanks for your reply! That certainly is a nice little colour organ! Unfortunately, after looking at the code that was used i started to feel dizzy! ha! I'm still very new to this and the road I've been going down so far seems to click a bit better for me. I still like the idea though so will definitely have a go at your method after i get this working!
You seem to be thinking along the same lines as me. You're right, the audio I'm using at the moment is coming straight out of the Ipod headphone jack (I'm just taking it from the amplifier input). This of course means that it depends on the volume of the ipod. I have some ipod plugs on the way from the netherlands which will allow me to take a line out feed directly from the bottom of the ipod.
At the moment I'm planning on just seven bar graphs, one for each frequency from the MSGEQ7. Is there a way to expand those seven frequencies from the MSGEQ7 into more? If so, i would like to eventually display a larger spectrum.
The TI TLC5940 you suggest appears to add PWM pins to the Arduino. Is this correct? My understanding is that the analog signals coming from the MSGEQ7 cant be reproduced through PWM.
The LM3915 requires just one limiting resistor to program the LED current. The rest is done internally :0) I'm using a 180 ohm resistor with a 5v supply.
Now...... with all that said, after posting this yesterday, i emailed the link to a friend who had a look and immediately sent me 2 options for achieving the result I'm after. He quickly "whipped up" some code and gave me a rundown of how to wire the circuit. In theory, it sounds perfect and after posting this I'm heading down to Jaycar to get some parts.
The idea is basically to use one LM3915 to drive seven multiplexed LED bar graphs. I always thought i'd need one LM3915 for each bar graph. Anyway, the Arduino would simply be used as a timer to signal the strobe and reset on the MSGEQ7 and to switch a transistor on each of the led bar graphs in sequence therefore allowing only one bar graph to display at a time.
Ive already tried this with two bargraphs on the breadboard and it seems to work well. Once i get the parts I'll wire it up, take a video and post the results.
The other option floated was to use a 555 timer and a decade counter to switch the transistors eliminating the need for an Arduino. This would be a preferable option if i was to box this project up! Would hate to hide my Arduino away in a dark box out of sight!
Once again thanks for your help guys! I've been kind of on the right road but just need that helping hand that only experience can give.
Once i get it up and running i'll post the results!