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View Full Version : Basic stamp 2, SN754410, 555 timer or 556 timer DC motor



enkei
09-22-2008, 08:55 AM
Basic stamp 2, SN754410, 555 timer or 556 timer DC motor how can i wire all this im confused in the way to wire all this together because of PWM

Mike Green
09-22-2008, 09:07 AM
Back up a few steps.

1) Do you understand how to use the SN754410? Do you know how to hook this up to your motor?

2) Why are you asking about a 555 timer or a 556 timer? Why do you want to use them?

3) What do you want your motor to do? Do you want to be able to reverse it? Do you want to control its speed?

4) Have you gone through the exercises in "What's a Microcontroller?". Do you understand how to do PWM with a Stamp?
Can you control the brightness of an LED using PWM with just a Stamp? There are some excellent tutorials and exercises
in the StampWorks manual and in several of the Nuts and Volts Columns that are downloadable from Parallax's website.
Have you found them? Have you looked at them? Have you tried a Google websearch for the SN754410 for sample
circuits and a datasheet?

azmax100
09-22-2008, 02:39 PM
I think this link can give you better picture,

http://www.bio-bot.com/privateweb/datasheets/powercontrol/SN754410app1.htm

enkei
09-22-2008, 09:42 PM
I do understand most of this i'll will send u a scan schematic of what i have so far and i want to make a ir sensor robots like a mice but with 4 motors and i need the 555 timer for PWM, also im using the 754410 for the motors and a bs2 as a microcontroller how do i wire all this.?

Mike Green
09-22-2008, 10:37 PM
I think you'd do better with something like the PWMpal (www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/txtSearch/pwmpal/List/1/ProductID/67/Default.aspx?SortField=ProductName%2cProductName (http://www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/txtSearch/pwmpal/List/1/ProductID/67/Default.aspx?SortField=ProductName%2cProductName)) .

This has 4 PWM outputs, functions independently from the BS2, and is simple to use. If you want to use a 555 timer, you'd also need some kind of digital potentiometer for each timer. The timers and digital potentiometers take space and would have to be duplicated 4 times, once for each motor.

Chris Savage
09-22-2008, 11:32 PM
You already had a thread on the SN754410. In the future please follow up on your original threads instead of starting new ones for the same subject. Take care.

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Chris Savage
Parallax Engineering

enkei
09-22-2008, 11:53 PM
ok thank you for your answers so far but, i need to explain my situation more in detail i have 4 motors. the PMWpal
has 4 outputs that already have PWM right. then dont i need another 4 outputs for reverse? and i think that my configurations is Bs2 to PWM
to the ENABLE of the 754410 the to the motors?

Mike Green
09-23-2008, 01:33 AM
Did you read the article mentioned by azmax100? That discusses how to control motor direction. The PWMpal produces the PWM signals which do go to the Enable/PWM inputs of the SN754410s. There would be two I/O pins per motor for direction and dynamic braking control.

enkei
09-23-2008, 02:10 AM
yeah now i did saw his message and is helpful can i still use the PWMpal? and so far i understand that i will use the PWMpal
to 2 of the SN754410 because i need 8 outputs 4 for foward and 4 for reverse and the PWM already has 4 outputs of PWM is this ok or
im going the hardway?

Mike Green
09-23-2008, 05:31 AM
You need to reread my message and reread the description of the SN754410

Why do you need 8 outputs?

enkei
09-23-2008, 06:54 AM
well mr. mike green i think am asking for 8 outputs because i need 4 to make the car forward and 4 if i needed to go reverse. the 754410 has only 4 outpus
and they will go to the posite of the motor and what about to go reverse and the negative side? this my schematic so far but without the 556 timer now that i have order the PWMpal

be80be
09-23-2008, 08:09 AM
Do you have 4 motors this thing drives 2 motors fw a rev with 4 pins it's from http://www.bio-bot.com/privateweb/datasheets/powercontrol/SN754410app1.htm

Mike Green
09-23-2008, 08:23 AM
The article by azmax100 and the drawing by be80be both show how to hook up a SN754410 to drive two motors. You'll need two SN754410 for 4 motors. The Enable/PWM connections go to the PWMpal pins. The direction connections (2) go to other pins. You'll need 8 I/O pins for direction control as I said earlier and the 4 PWM pins from the PWMpal for a total of 12 I/O pins.

enkei
09-23-2008, 08:24 AM
i have seen that drawing but i have two more motors band that 754410 outputs are taken already by having 2 fwrd and two rev that is why i need another 754410 right?

enkei
09-23-2008, 08:26 AM
thank you mr. green so im in the right track?

Mike Green
09-23-2008, 08:39 AM
One SN754410 can control two motors if you want to have them go forward and reverse (two full H-bridges).

One SN754410 can control four motors if you want to have them go in only one direction (four half H-bridges).

be80be
09-23-2008, 08:44 AM
If your going to drive 4 motors are thay just to make it move fw and rev Like 2 motors on the right and 2 on left?

enkei
09-23-2008, 08:44 AM
·········· the motors need to go foward and reverse. if i want to turn i will have the two motors on the right to go foward and maybe the left on ereverse to turn faster. is this ok?

be80be
09-23-2008, 08:58 AM
If thats what your doing then you could hook the right motors in parallel and the left allso in parallel use just 1
SN754410 as long as your motors pull less then 1 amp per set.

enkei
09-23-2008, 09:19 AM
················· thank for following up yes i can do that, and yes i think it does pull less than 1 amp is one of those fa-130 motors but to
use the full power of the motors if i dont put them in parallel they will run better no? and if i connect 1 sn754410 to the 4 motors this
will heat up the sn754410 faster because i saw that it has a port for heat sink and ground and will shutdown· if over heats. that is another reason
i wanna use 2 instead of just one. is this ok or no?

be80be
09-23-2008, 09:33 AM
you shouldn't have and problem runing 4 of them should have 200ma to spare but don't thay just use 3volts

Post Edited (be80be) : 9/23/2008 2:38:47 AM GMT

enkei
09-23-2008, 09:42 AM
············· dont know i think it depends, but i just would like to use 2 754410 so they dont over heat, and use al 4 output of the PWMpal that i order and i think i ned a ADC0831 to use my sharp ir is the 120 anolog

Chris Savage
10-01-2008, 01:59 AM
enkei, your duplicate post was removed. You are starting too many threads on this same subject. Please follow up in one thread for additional questions on the same subject.

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Chris Savage
Parallax Engineering

enkei
10-01-2008, 03:53 AM
the reason that i dont follow up is that either they dont answer me or they answer the question and i dont right in the same topic because is different or they dont go and check if i added stuff

Chris Savage
10-01-2008, 09:49 PM
enkei, just because you’re not getting the answers you want doesn’t mean start new threads. As long as the threads are on the same subject they will be removed. There’s no reason you cannot follow-up on your thread and try to clarify what you’re looking for. There are no guaranteed replies here. If someone has something to offer and wishes to share they will reply. You can force replies from others. Adding stuff does not constitute a new subject.

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Chris Savage
Parallax Engineering

enkei
10-03-2008, 02:42 AM
alright then if you can help me with this question that i have. what is the PWM that i need in my enable 1,2 and 3,4 of my sn754410 to make the motors work, or what is the frequency that i need ? I made a 555 timer circuit and i get 2kHz in my output.

Post Edited (enkei) : 10/2/2008 7:48:17 PM GMT

Chris Savage
10-03-2008, 03:58 AM
There is no easy answer to your question…frequency is only one part of the equation. For a PWN driver you will typically have a fixed period or frequency and what you will be varying is the duty cycle or on/off time percentages.

For the most part the output will be somewhat non-linear, but assuming it was in an ideal circuit a 25% duty cycle would yield ¼ speed and a 50% duty cycle would yield ½ speed. 100% would obviously mean the motors were at full speed.

So if you’re going to generate a 2 kHz signal, you still need to be able to vary its duty cycle. Note that, at that frequency (audible range) you will likely hear a ringing or whine from the motors as they ramp up/down.

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Chris Savage
Parallax Engineering

enkei
10-06-2008, 08:37 AM
my DC motors from tamiya with voltage at 5v died even drop the voltage why?

enkei
10-07-2008, 05:37 AM
···· also my 754410

has voltage in the output pin even when there is no input or 1,2 enable. why?