Show Posts
Pages: 1 2 [3] 4 5 6
31  Using Arduino / Motors, Mechanics, and Power / Re: Help identifying some salvaged motors, wiring, voltage, etc ? on: April 14, 2013, 07:50:17 pm
The parts coming from the floppy are likely to use 12V or 5V, minus the driver drop.
The way I guesstimate the voltage of unknown steppers is apply a voltage to 2 windings out of the 4 available and wait for the temperature rise. Then I slowly increase voltage until the temperature stabilizes around 70C (some steppers can take more but without a datasheet it's best to keep a safety margin).
You can probably use this technique for the solenoid/dc motor, maybe with lower temperature rise.
32  Using Arduino / Audio / Re: Midi - Musical Instrument Shield - Volume Problem on: April 09, 2013, 02:33:17 pm
Looks like the instrument shield is ok and it's quite normal that it's not able to drive a speaker withouth an amplifier.

Does your amp works well if you plug it to an mp3 player/cell phone?

You can try plugging the instrument shield in a guitar amp.
33  Using Arduino / Audio / Re: Midi - Musical Instrument Shield - Volume Problem on: April 08, 2013, 10:22:30 am
There must be something wrong somewhere, with an half watt speaker you should hear the sound quite well.

Maybe you damaged the vs1053 output, I can't help more since I don't have this device.
34  Using Arduino / Audio / Re: Midi - Musical Instrument Shield - Volume Problem on: April 07, 2013, 07:10:08 pm
You could use a higher velocity, if the volume control is logarithmic it can make a huge difference.
If it's still not enough you can try to boost the gain of your amplifier
https://www.sparkfun.com/tutorials/392#gain_resistors
35  Using Arduino / Audio / Re: Midi - Musical Instrument Shield - Volume Problem on: April 07, 2013, 03:08:26 pm
what kind of midi commands are you sending? maybe you set the note on velocity too low
36  Using Arduino / Motors, Mechanics, and Power / Re: Driving a step motor model FL39ST34 on: April 07, 2013, 02:51:19 pm
You can follow the official stepper page
http://arduino.cc/en/Reference/StepperUnipolarCircuit
37  Using Arduino / Motors, Mechanics, and Power / Re: Driving a step motor model FL39ST34 on: April 07, 2013, 02:45:16 pm
if you bought the four leads version, you can't.
Else connect the winding centers to pin 9 and 12V and the other wires to the uln outputs.
38  Using Arduino / General Electronics / Re: Connecting an Oscilloscope to Opto-coupler? on: April 04, 2013, 01:27:09 pm
Why do you want an optocoupler between the Attiny and the oscilloscope?
You need to power the optocoupler, if you use the Attiny +5V, you defeat the optocoupler's purpose.
You could use another +5V power supply, connect it's +5V/gnd in place of the arduino, connect the oscilloscope ground to the same ground (pin 5) and the probe to pin 6
39  Using Arduino / Displays / Re: Cycling through screens while displaying live data on: April 03, 2013, 11:10:15 am
You got the screen cycling because you have to register that the button went from a high to low value.
If you just test if the button is low, this is true until you release the button.
So you can add a delay just like you did or keep the previous value to be able to compare.
40  Using Arduino / Audio / Re: Fully Rectified Sine Wave With PWM on: April 03, 2013, 10:58:19 am
With the help of my old ti85:


Code:
  float a = 255.0;
  float b = 255.0;
  float c = 28000.0;
  float d = 2.0;

void loop() {
{
  int value = a - b * abs(sin(d*PI*millis()/c));
  analogWrite(2,value);
}

You'll get a full intervall each 14s
41  Using Arduino / Audio / Re: Fully Rectified Sine Wave With PWM on: April 03, 2013, 10:45:13 am
If you want to rectify a sinus you have to use abs(sin...)
in your case -abs since you want to invert it.
42  Using Arduino / Displays / Re: Cycling through screens while displaying live data on: April 02, 2013, 02:10:23 pm
You have to keep calling the function that displays something.
Rethink your loop a bit.

have a variable hold the screen number, let's call it screen.
int screen=0;

int the loop:
Get the data
Check for button press // better add a debounce too, check in the examples I think there's something there.
if press -> add 1 to screen
if screen == 4 -> screen =0

display.clearDisplay();   

if screen==1
    time();
if screen==2
    mainScreen();
if screen==3
    maintenance();

That way even if no button is pressed, the screen is refreshed
43  Using Arduino / Displays / Re: Newbie problem: Displaying integer value on Nokia 5110 display on: April 02, 2013, 12:19:04 pm
Notice that for gotoXY:
 * x - range: 0 to 84
 * y - range: 0 to 5

If you use gotoXY (1,2) and gotoXY (1,4) you should be able to add lines in between the ones you already have.
To add a bargraph on top you just need to
gotoXY(0,0);
Then send 84 bytes describing what you want to display with
LcdWrite(LCD_D, mybyte);
For example
LcdWrite(LCD_D, 0x55);
LcdWrite(LCD_D, 0xAA);
LcdWrite(LCD_D, 0x55);
LcdWrite(LCD_D, 0xAA);
LcdWrite(LCD_D, 0x55);
LcdWrite(LCD_D, 0xAA);
should display a checkers pattern
44  Using Arduino / Motors, Mechanics, and Power / Re: Proper generate of Pwm Stepper Motor on: April 01, 2013, 08:12:28 am
A DS1044? A delay line ic? I'm missing something here.
45  Using Arduino / Displays / Re: how to make 2 rows in Serial Display? on: March 31, 2013, 08:13:23 am
You should count the characters and when you reach 16 jump to the second line


Code:
void loop()
{
  // when characters arrive over the serial port...
  if (Serial.available()) {
    // wait a bit for the entire message to arrive
    delay(100);
    // clear the screen
    lcd.clear();
    int nbchars=0;
    // read all the available characters
    while (Serial.available() && i<16) {
      // display each character to the LCD
      lcd.write(Serial.read());
      nbchars++;
    }
    lcd.setCursor(0, 1);
    while (Serial.available()) {
      // display remaining characters on the second line
      lcd.write(Serial.read());
    }
  }
}
Pages: 1 2 [3] 4 5 6