Saturday 26 September 2009

Switching the lights on

I swapped back to "playing" with my believed-to-be working stepper motor driver board. Looking back, I found Nophead's comment about connecting the enable pin to 0V in order to get the indicating LEDs working. I established from the instructions that the enable pin was pin 5 on the IDC socket, but I didn't know which was pin 5.

After some internet hunting, I eventually managed to confirm the identification of the pins relative to the ribbon cable wires. I thought. I tried that, and got nothing. Hmmm. After some more hunting, I found that my reference website had been wrong - but they're in good company, as Asus apparently got it wrong in their manuals and on their own website! Luckily, this being a communication type connection rather than power, nothing drastic happened when I'd connected the wrong pin.

Using this website, I got the right diagram.
Wire 1 on the ribbon cable goes to pin 1 on the IDC, which is at the end of the row adjacent to the tab on the male connector, shown here as on the top left of the connector, and pin 5 is marked with a wire.


In order to test the stepper motor driver board's indicating LEDs, the pin on the board's connector corresponding to pin 5 on the ribbon cable is connected to ground.
Here is a photo' showing the connector pins 5 (enable) and 9 (ground) linked with a wire.



After arranging this, I plugged in and switched on power to the working board - sure enough the LEDs lit, but one green on one side and one red on the other. Is this correct? Anyone know which ones are supposed to light up?

2 comments:

  1. Yes one of each pair of LEDs should be on. I think it will be pretty random because the reset pin of the chip is tied high so it doesn't get explicitly initialised.

    If you connect a motor then you should be able to control the intensity of the LEDs with the current control.

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  2. My motors aren't yet wired....

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