Subject:
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Re: Using 30VDC to drive motors
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Sat, 21 Nov 1998 23:00:28 GMT
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Original-From:
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Matt Harlan <mjh10@cornell*StopSpam*.edu>
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Viewed:
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2226 times
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Dave
As far as connecting the grounds, that just means that the HB and the
motors must share a common ground. The H-bridges need to reference the
direction and PWM signal to ground and if that ground reference is not the
same as the HB's the motors flip out.
I used the motor power header for the gorund so that the motor supply
ground runs throught the on board choke before it get's to the digital
ground on the HB. Motor are noisy and can cause the HB to reset.
> "Make sure the supply ground for the 18200's is connected to the HB ground.
> You'll get some very strange results if you don't. Use the motor supply
> header on the HB for this connection. You can take advantage of the noise
> filtering of the HB that way."
> First, does this mean that I should connect the HB ground to the 30VDC ground
> I'm using to power the motors?
YES.
> "The motor control routines in IC are completely compatible with the 18200's.
> The enable lines for the HB motor chips go to the PWM line on the 18200's.
> The direction lines from the HB go to the direction line on the 18200's.
> HB pin 1 to PWM motor 1
> HB pin 2 to direction motor 1
> HB pin 9 to PWM motor 2
> HB pin 10 to direction motor 2"
>
> Second, the does the pinout given above refer to the motor ports on the
> handyboard? If so, there is no connection on pin 2, and pins 9 and 10 • refer to
> two different motors!?
It's been awhile since I had the HB out, but if memory serves me, those
should be right. The connections are from the chip sockets for the on
board h-bridges, to the 18200.
after checking the schematics, the connections are right. Pin 1 on the
L293 serves as the PWM input to the 18200, and Pin 2 is the direction. Pin
2 should be a direction connection from the '374 latch on the HB, and Pin 7
is its complement via an inverter. Are you sure pin 2 is not connected?
I used a 16 pin DIP header for a ribbon cable to get the connection. Pin 1
and 2 on the L293 socket to one 18200 and 9 and 10 to the other 18200.
Pins 9 and 10 should be setup the same way as pins 1 and 2.
I'm not sure if that clears things up even a little.
if not, tell me exactly what is connected and what isn't working, and we'll
go from there.
good luck
matt
______________________________________________________
Matthew J. Harlan
Cornell University Cornell Formula SAE
Electrical Engineering Engine Management
(607) 255-2541
mjh10@cornell.edu
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Message is in Reply To:
 | | Using 30VDC to drive motors
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| Hello, I have finished building Matt Harlan's H-Bridge circuit (from the Handyboard FAQ) and I have come across the following instructions: "Make sure the supply ground for the 18200's is connected to the HB ground. You'll get some very strange (...) (26 years ago, 21-Nov-98, to lugnet.robotics.handyboard)
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