Basic stamp 2, SN754410, 555 timer or 556 timer DC motor
enkei
Posts: 23
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
Comments
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?
http://www.bio-bot.com/privateweb/datasheets/powercontrol/SN754410app1.htm
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.
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Chris Savage
Parallax Engineering
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?
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?
Why do you need 8 outputs?
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
One SN754410 can control four motors if you want to have them go in only one direction (four half H-bridges).
SN754410 as long as your motors pull less then 1 amp per set.
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?
Post Edited (be80be) : 9/23/2008 2:38:47 AM GMT
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Chris Savage
Parallax Engineering
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Chris Savage
Parallax Engineering
Post Edited (enkei) : 10/2/2008 7:48:17 PM GMT
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
has voltage in the output pin even when there is no input or 1,2 enable. why?