With the array I got from spectrum analyzer, which is size of 7, I need to create another array with size of 175. Then I need to load this to 22 shift registers and then release the parallel data. This will be done over and over again, very quickly, since the LEDs have to be synced with the audio.
Would I experience any time delay between the actual serial data and its representation on LEDs ?
Yes, you are ok just using some 74HC595 shift registers to drive LEDs. Have proper resistors to limit the current. These shift registers are meant to drive signal lines, not high-power LEDs. You may chain them into a good length. Just make sure you wait long enough between shifting out the last bit and latching the values out. It takes time to propagate the bits to the last shift register. If you see your last few LEDs always lit or blinking and not doing what they should do, that is when you latch out the values too soon. The LED driver from sparkfun probably has current limitation built in and needs no resistors. Here is a cheap source of the 595s
I don't know if this is discussed before (Probably has been) but I couldn't find any document, that's why I am asking.
I want to build a PCB and when I place the processor on it, it will work as arduino. To do so, I need to combine some components like crystal clock, capacitor and stuff like that but don't know what I exactly have to do. Is there a guideline for this ?
Just wrote down a basic square wave to drive the transformer which is 230V AC input and 11V AC output. This was a transformer extracted from a Guitar amplifier. Connected the arduino from 11V side and expected to see at least half of the 230 V (If I'm not mistaken arduino supplies around 3V, right)
However when I touched the LED to 230 V side of the transformer, LED was barely blinking with a pale light.
What might be wrong with this ? Why the voltage drops even under the 5V when it passed through the transformer ?
this is the function and calling this function by writing down check(); statement whenever I want to check the condition to interrupt the if statement would work I think. Don't have the board with me, so can't test. But this is my idea.
Actually I have a circuit built on a matrix board working with 555 timer to get a square wave, however couldn't get it worked. Thought programming the arduino on computer to get an AC current , but apparently not that easy to do.
Have a 230V to 11V transformer. Want to run it to have a spark gap. First thought creating an Sine Wave would be easy with arduino but apparently not that easy.
Just a couple of thoughts here... first, don't use "normal" transformers this way. They're not very good at it. If you want a spark gap, use a high-frequency ferrite core transformer, like the baby flybacks you find in plasma globes. You may get a painful shock/small burn if you're not careful, but you're quite unlikely to die unless you decide to experiment with it naked covered in salt water.... so don't do that :p
Also, don't throw a microcontroller at a project that doesn't need one. It'd be easy enough to knock together a 555-based oscillator with some big fat power transistors to make an appropriate driver circuit, and a lot less hassle if you burn something out. Google "flyback driver 555" for some ideas, it's not difficult. You can vary the output voltage by varying the duty cycle of the 555 oscillator.
I'm using the push button with the built in pull-up resistor;
and have such a main loop. Whenever I press the push button and hold, the empty string called "pass" takes dozens of "1", as expected However I want to make it sense the push once until I release it and push again. By that structure, it is not likely to implement I think.