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1  Using Arduino / Project Guidance / Re: 11 band audio visualizer on: July 05, 2014, 02:57:56 pm
did a bit more work after some fireworks smiley-grin. the BP filter graph looks good, but the peak detection is weird even though its the same circuit copied + paste.

top image is the log plot and the bottom is just a regular linear one. in each image top is the peak detection, lower is after the bandpass. These are with a Q value of 7.
2  Using Arduino / Project Guidance / Re: 11 band audio visualizer on: July 04, 2014, 06:33:44 pm
yeah i know i need 11 haha, i just hadn't gotten to the copy+paste as i wanted to test one first. i also found that site. its what lead me to use the Multi feedback band pass filters and was extremely useful for understand all this stuff. i found a calculator for the bandpass here: http://sim.okawa-denshi.jp/en/OPtazyuBakeisan.htm
im currently putting in cap/resistor values to the scheme and finding the best Q value.

also, good tip on the reference voltage. that would make an easy way of getting the full 0-1023 range in software.

attached is the graphed output of four of the bands. top is the peak detector output (thanks to a EEVblog video for the design) and the bottom is the output from just the bandpass filter.

here is the link to the design https://www.circuitlab.com/circuit/5rc4yq/audio-visualizer/
3  Using Arduino / Project Guidance / Re: 11 band audio visualizer on: July 04, 2014, 05:33:01 pm
Ive been researching the last few hours and stumbled upon circuitlab.com which should allow me to fine tune this circuit. Im getting all excited just thinking about using it.

here is the test of the 20Hz band pass and peak detector (files attached). graph was produced with a 1Hz to 20khz sweep. Band pass definitely needs some tweaking, but this program will be a HUGE help in designing this.

I totally admit this stuff is a bit over my head, but with this program and some reading i think ill be able to see this through!
4  Using Arduino / Project Guidance / Re: 11 band audio visualizer on: July 04, 2014, 02:52:27 pm
maybe magnitude was the wrong word, would it work as intended though? Or what would you recommend to get those 11 bands?

ill look into the multiplexer, thanks.
5  Using Arduino / Project Guidance / 11 band audio visualizer on: July 04, 2014, 02:31:00 pm
Im working on a 11 band visualizer that uses an 11x9 LED matrix to display the bands. I have the LEDs figured out (565 shift registers with PNP and NPN transistors to power the columns and rows for multiplexing), but i need to figure out how to analyze the audio. I know of the MSGEQ7, how ever that is only 7 bands. I also thought of using processing and the minim library + FFT but id like something that doesn't need a computer to work.

Next i found some graphic equalizer schematics based on the TL074 such as the one below.

I should be able remove the pots (which recombine the audio bands back into one) and connect each opamp to an analog input on an Arduino and from there be able to read the magnitude of each band, correct? if so, the problem is I don't have 11 analog inputs.  So, is there some sort of shift register like the 74hc164 that does analog instead of digital inputs? Or any chip that can cycle though inputs for that matter.

Finally, thanks to this page http://www.geofex.com/article_folders/eqs/paramet.htm ive sort of figured out how to calculate the capacitance values to set the frequency range. This is what i was thinking of: 20,40,60,100,300,500,1k,2k,4k,9k,18k

so, what do you think?
6  Using Arduino / Programming Questions / Re: Very strange OBDuino power issue. on: June 05, 2013, 10:00:54 am
so it seems something is wrong in the code + how it reads the info from my car, but that just sparked an idea. since the iso9141 interface is still not working, it could be causing it to set the wrong contrast.

around 60-70 the contrast looked how it should. now its just this interface error smiley-sad any tips?

im now using a si9243 (MC33290 replacement), just to rule out any issues with the converter. it has been checked working in the obduino project here: http://ecomodder.com/forum/showthread.php/freescale-mc33290-replacement-19692.html
ive followed it exactly except the 100 ohm, the diode, and the extra 12v from the cig lighter (design fail by that person smiley-wink).

i should try it on another car. Ok, tried two others. still no go smiley-sad smiley-sad has to be something with the hardware
7  Using Arduino / Programming Questions / Re: Very strange OBDuino power issue. on: June 04, 2013, 10:57:03 pm
derp. lets do some troubleshooting. ill load up a program that enables the lcd blah blah blah and do a for loop to change the contrast. should eliminate something smiley

 Ill let you guys know how it goes.

if anyone cares; code:
Code:
#include <LiquidCrystal.h>

#define LCD_RS 4
#define LCD_ENABLE 5

#define LCD_DATA1 7
#define LCD_DATA2 8
#define LCD_DATA3 12
#define LCD_DATA4 13

#define LCD_COLS 16
#define LCD_ROWS 2


// LCD Pins same as mpguino
// rs=4, enable=5, data=7,8,12,13
LiquidCrystal lcd(LCD_RS, LCD_ENABLE, LCD_DATA1, LCD_DATA2, LCD_DATA3, LCD_DATA4);
#define ContrastPin 6
#define BrightnessPin 9

void setup() {
  lcd.begin(LCD_COLS, LCD_ROWS);
  analogWrite(BrightnessPin,150);
  delay(100);
  // Print a message to the LCD.
  lcd.print("hello, world!");
}

void loop() {
  for (int i = 0; i<255; i+=2)
  {
    analogWrite(ContrastPin,i);
    lcd.setCursor(0, 1);
    lcd.print(i);
    delay(400);
  }
  //51 sec to do a cycle

  for (int i = 255; i>0; i-=2)
  {
    analogWrite(ContrastPin,i);
    lcd.setCursor(0, 1);
    lcd.print(i);
    delay(400);
  }
}
8  Using Arduino / Programming Questions / Re: Very strange OBDuino power issue. on: June 04, 2013, 10:24:26 pm
i finally took the time (5 min lol) to put in the resistors. still have the contrast issue smiley-sad

and i still haven't got the actual k line interface working either so smiley-sad
9  Using Arduino / Project Guidance / Re: Simulate push button with arduino on: May 22, 2013, 01:20:27 pm
is teh diode connected right? the flow goes to the arduino (see that pic i made on the last page) a diode only lets current flow in one direction, to specify this, diodes generally have a one colored body with a stripe at one end. whatever end the stripe is on is the only way current flows. if the black is to the left and the stripe is on the right, current flows left to right.
10  Using Arduino / Project Guidance / Re: Simulate push button with arduino on: May 22, 2013, 11:40:00 am
never ran into that problem before, maybe try one of those glass diodes?

and ill wait to see what someone else say for those other pads (.6v ones)
11  Using Arduino / Project Guidance / Re: Simulate push button with arduino on: May 22, 2013, 07:19:28 am
Quote
So for the center pad do you think that a IN0001 to the +2.34V terminal will do the trick?
Yes.
12  Using Arduino / Project Guidance / Re: Simulate push button with arduino on: May 21, 2013, 06:02:32 pm
the first one is pulled up to ~2.3v so that when gnd is connected to that center pad, the MCU senses gnd, and the 2.3v goes to gnd through the resistor (so it doesn't create a short to ground). thats really strange for the other pads. .6v shouldnt be enough for a mcu to sense.

so for the center, you just need a diode. please check the other two again.
13  Using Arduino / Project Guidance / Re: Radioshack LED strip (Power Issues??) on: May 18, 2013, 02:06:43 pm
ahhh yes good point on the rev polarity!
14  Using Arduino / Project Guidance / Re: Radioshack LED strip (Power Issues??) on: May 18, 2013, 01:46:11 pm
it has to be pos tip. you probably blew the voltage regualtor on the arduino so it only works on usb
15  Using Arduino / Project Guidance / Re: Radioshack LED strip (Power Issues??) on: May 18, 2013, 11:46:01 am
ignore all the led strip stuff and try pluging in just the barrel plug, does the arduino light up? (the ON led)
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