MMBe (Motor Mind B enhanced) Circuit Diagram

Bill Chennault

All--

I think I have misinterpreted the Motor Mind Be circuit diagram in the documentation that shows it interfaced to a Stamp. (The circuit is shown below.)


The two 12VDC connections, especially the one on the MMBe, confused me. I thought the MMBe 12VDC connection referred to an example using a 12VDC motor. Upon reflection, I believe it refers to the same 12VDC supply used to run the Stamp.


Is that correct? If so (and with the tiny motor with which I am testing), I could run the motor off the Stamp's regulated·power supply via MMBe pin 1 (5VDC) and MMBe pin 2 (GND). However, that is not what I WANT to do. I want to run the motor from a seperate supply, such as my variable power supply. It is not obvious to me how that is done by modifying the circuit below. I know it must be simple, but so am I.

For your information, I plan to mount the MMBe in the breadboard area of my BOE Rev. C.

Can you help? (As always, please correct any incorrect assumptions I have made.)

Thanks.

--Bill

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You are what you write.

Mike Green

You can connect the + from your variable supply to VMOTOR and the - from the supply to GND. You need to tie this GND together with the BOE (and Stamp) GND. Just for discussion, if you wanted to run the MMBe from a regulated +5V supply, you really could not use the supply on the Stamp. The BOE does have its own +5V regulator and that would be ok. The issue is that the Stamp's regulator doesn't really have enough capacity to power a motor.

Bill Chennault

Mike--

I still find myself using the wrong terminology. When I said . . .

I could run the motor off the Stamp's regulated power supply said...

I really meant the BOE's supply. Thank you for pointing out the difference. Sooner or later it will stick. Hopefully, it will stick before it smokes.

I will give it a try and see what happens! (Big deal for me! <g> )

--Bill



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You are what you write.

Bill Chennault

Mike (and All)--

Ha! That Motor Mind Be is pretty neat! (Thanks for setting me straight, Mike.) You can even plug it in the breadboard backwards, apply power to it several times, figure out what you did wrong, turn it around and it works perfectly! Now, how can you beat a deal like that? (I should'a posted the picture I took of the setup along with the schematic. You would have spotted my mistake instantly.)

What I did was download the Solutions-Cubed Motor Mind B "exercise" code, debugged it (not difficult), and it ran perfectly.

--Bill


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You are what you write.