floppy BLDC

Using Arduino Programming Questions
1

i have a floppy motor and driver like: http://sturntech.com/blog/2010/12/04/reverseengineering-fd1231h-floppy-disk-spindlemotor-controller/

i figured out that if i loop LOW then HIGH with no delays on the CLK pin with the arduino(vcc etc hooked up too), it will turn the motor. but its really laggy, how can i speed up the LOW/High switching of the digital pin and thus make the motor spin "better"?

2

how can i speed up the LOW/High switching of the digital pin

Use direct port access rather than the digitalWrite function.

3

ok so i have clock on pin 9 and using the old digitalwrite code it works, but if i use this:

int DlY=10;
void setup() 
{                
  DDRB=11111111;   //sets 8-13 as output   
}

void loop()
{
  PORTB = B11111111; //sets 8-13 as high
  delay(DlY);
  PORTB = B00000000; //sets 8-13 as low
  delay(DlY);
}

it doesn't...how long does it take for a normal digitalwrite? ive confirmed that the pin is actually cycling.

4

it doesn't...how long does it take for a normal digitalwrite?

Orders of magnitude less than the delay().

5

the website i linked before said to put a 1mhz clock on this pin, am i even doing the right thing toggleing LOW/HIGH?

hmmm thats strange, before with no delays and new code it wouldnt turn, now it does but very slowly but its smooth...

6

I hope it said 1MHz, and not 1mHz

7

yes 1MHz sorry

8

before with no delays and new code it wouldnt turn, now it does but very slowly but its smooth.

So it looks like it is producing pulses that are too fast without the delay.

9

im so very confused.. O-scope would be so nice right now...

can you help a little more?

10

You have a 10 millisecond delay. Try cutting that down to smaller delays. If one millisecond delay is still too long (i.e. the speed is not where you want), you can use delayMicroseconds() to get shorter delays.

If shorter delays don't help, more voltage, or current, or both might.

11