motor shield question

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supernoob
 
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motor shield question

Post by supernoob »

Could someone help me please. i am brand new and need some advice. let me know if this is possible and what product will work.

i need to control a precision brushless continuous servo motor. it only needs a control signal. the power is already taken care of with a dedicated large power source. the control input has these specs: 5-24VDC digital PWM input, frequency range: 20Hz to 30 kHz, PWM duty cycle, 6.3mA limited

the speed is controlled by the duty cycle of the PWM. So I just need a PWM with 0-100% variable duty cycle.

Is there a shield that will control this? i see most of the options on the Adafruit motor shields are for amp ranges that power. Will my control input just ignore this and only take the 6.3 mA that is needed?

Also I have a second part to my question. I would like to change the speed with an analog control voltage signal. It will be 0-5V and 2.5 mA. Can I just send this into an Arduino analog input and then program it to control the PWM duty cycle motor shield out?

I would really appreciate some advice. Thanks a lot!

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adafruit_support_bill
 
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Re: motor shield question

Post by adafruit_support_bill »

The Arduino itself is capable of generating a 5v PWM signal in that frequency range. You do not need a shield, although something like a proto shield or a wing shield are handy for making connections to the Arduino.
http://www.adafruit.com/products/51
http://www.adafruit.com/products/196

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supernoob
 
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Re: motor shield question

Post by supernoob »

thanks for the timely response bill.

i just thought this shield, Adafruit Motor/Stepper/Servo Shield for Arduino v2 Kit - v2.0 would give me higher resolution and no jitter than the stand alone arduino. i really like that 16 bit servo output and dedicated PWM no jitter setup.

could you also answer this last question:

with that motor shield could i use the SERVO OUTPUT's control and ground wire only? and not connect the third power wire? it has it's own power and only needs a control signal. 0-100 % duty cycle range.


thanks again for the help.

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adafruit_support_bill
 
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Re: motor shield question

Post by adafruit_support_bill »

i just thought this shield, Adafruit Motor/Stepper/Servo Shield for Arduino v2 Kit - v2.0 would give me higher resolution and no jitter than the stand alone arduino.
The servo outputs on that shield are connected directly to Arduin digital pins 9 and 10. There is no difference between that and a direct connection to the Arduino.

We do have a 16 channel, 12 bit PWM servo shield: http://www.adafruit.com/products/1411 But that doesn't operate at the 20-30KHz your motor needs.
with that motor shield could i use the SERVO OUTPUT's control and ground wire only? and not connect the third power wire? it has it's own power and only needs a control signal. 0-100 % duty cycle range.
Yes, that is possible. But as noted above, it would be equivalent to connecting directly to pin 9 or 10 on the Arduino.

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supernoob
 
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Re: motor shield question

Post by supernoob »

just when u thought u got rid of me. :) 1 more quick question.

do you know if the Teensy 3.0 has a PWM output that is 5V or higher? work with my above specs.

thank you!!

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adafruit_support_bill
 
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Re: motor shield question

Post by adafruit_support_bill »

The Teensy 3.0 is a 3.3v device. Still, you could use the PWM output to drive a transistor to switch 5v.

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supernoob
 
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Re: motor shield question

Post by supernoob »

TXB0108 will work with the teensy 3.0 pwm output?

https://www.adafruit.com/products/395

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adafruit_support_bill
 
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Re: motor shield question

Post by adafruit_support_bill »

That should do it!

elmimiliano
 
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a new question!!

Post by elmimiliano »

Hello, im emiliano from argentina, i have a stepper/DC/servo Adafruit driver control...and i have and arduino uno board: i have a question about if i can control a 24v stepper motor with adafruit driver and UNO only or if a need external energy suplied. In fact, i have a problem because i did tue conections and my motor works at first, but the not, i couldn't make it works. So, why at first it works without batteries supplied...and then not?? I dont undertand. please...can you help me???



pd:
the motor is :http://www.BANNED.com/pdf/motors/PM42S-048-HHC8.pdf

sorry for my english

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adafruit_support_mike
 
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Re: motor shield question

Post by adafruit_support_mike »

Please don't post the same question in more than one thread, and please start a new thread instead of adding questions to a thread where we're already helping someone else. Things just get confusing that way.

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