Hi all,

I'm looking for any advice I can get on controlling a small DC motor with digital logic. I think it would be easier to break up the project so I can learn for myself too!

1) Create a clock on some digital logic

2) Motor turns on for set amount of time then stops

3) Motor turns on from a pre set trigger (i.e turns on in the morning)

4) After motor turns off- reverse polarity of driving circuit

I have studied digital electronics but as with much else with academic study... I have no idea how to apply it.

Any help would be much appreciated

Thanks
Matt

 

The next step is to define the interfaces between your various parts more specifically. For instance, you might break the project into three parts:

1) Clock
2) Motor driver
3) Motor control logic

The clock sends its output to the motor control logic and the motor control logic sends its output to the motor driver.

Then you need to decide how you are going to parse out the functionality. For instance, do you want the clock to send signals telling the motor controller to turn on and turn off and also which direction to run? Or do you want the clock just send a trigger signal to the motor controller and have it be responsible for turning the motor off and keeping track of which direction the motor should turn next? You can do it either way and which is best may be obvious when you consider what your eventual goals are or it might end up being a coin toss. The important thing is that you have to make a decision and proceed.

 

I think it would be best for the clock to relay signals to the motor controller that way I can add another device (i.e. LDR for light sensing) so that the motor will start when either a preset time is passed/ the light level is correct.

 

Okay, so now start describing what the signals are that will be passed between the clock and the motor controller and between the motor controller and the motor driver. You need to specify thing like how many signals, what kind of signals, what information the signal conveys, and what the receiving side is supposed to do in response to seeing that signal.