BASIC Stamp: Which one to get?

[Oznog]

Say this comes to mind. In an argument over whether a PIC could be a very reliable PWM motor controller (a foolish argument to me, of course it can be if done correctly) someone said that in a high noise environment you should be sure to put the reset on the pin rather than use an internal reset feature.

I could see that as useful if the reset pin was going to have an external reset pulling it down if some sort of external reset was necessary, yet no such feature was discussed. It would seem to me that noise on the external wiring and power supply spikes would be much more likely to mess with an external reset pin. Agree or disagree?

 

[Nigel Goodwin]

Say this comes to mind. In an argument over whether a PIC could be a very reliable PWM motor controller (a foolish argument to me, of course it can be if done correctly) someone said that in a high noise environment you should be sure to put the reset on the pin rather than use an internal reset feature.

I could see that as useful if the reset pin was going to have an external reset pulling it down if some sort of external reset was necessary, yet no such feature was discussed. It would seem to me that noise on the external wiring and power supply spikes would be much more likely to mess with an external reset pin. Agree or disagree?

I suspect there's no 'perfect' solution, each might be better under certain circumstances? - probably the most important advantage of using an external reset pin is that you can add an external 'brown out' circuit.

 

[coastergeekrtc]

Wait, I've heard of the PWM Module but never knew what it did. So it can control motor speed? Will this work with my 14V motor so that I don't need to use a realy to switch between a reverse and forward state, in which reverse runs at a low voltage?

 

[Oznog]

Wait, I've heard of the PWM Module but never knew what it did. So it can control motor speed? Will this work with my 14V motor so that I don't need to use a realy to switch between a reverse and forward state, in which reverse runs at a low voltage?

It can lower the effective voltage that the motor sees, thus controller the motor speed. You will need an external transistor. A reversible implementation is easy too, but you'll need 4 transistors and 2 different PWMs (most PICs with PWM have 2 different PWMs on it).

 

[coastergeekrtc]

Is there any site I can go to to help me with the PWM? And if I want a high voltage forward speed and low voltage reverse speed, will PWM do that? From the looks of it, the 16F628A has only one PWM, so I would need to get one with two if I want to reverse the motor, right?

 

[Nigel Goodwin]

Wait, I've heard of the PWM Module but never knew what it did. So it can control motor speed? Will this work with my 14V motor so that I don't need to use a realy to switch between a reverse and forward state, in which reverse runs at a low voltage?

It can lower the effective voltage that the motor sees, thus controller the motor speed. You will need an external transistor. A reversible implementation is easy too, but you'll need 4 transistors and 2 different PWMs (most PICs with PWM have 2 different PWMs on it).

Only the larger PIC's have two PWM's, but you can design an H-Bridge so it only requires one PWM signal, and is reversed by a single pin (most H-Bridge chips are designed like this).

 

[coastergeekrtc]

Will this H-bridge work? https://www.robotroom.com/HBridge.html