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Topic: Run motor from rc helicopter through Arduino (Read 2 times) previous topic - next topic

yosler

Aug 12, 2013, 03:36 am Last Edit: Aug 12, 2013, 03:39 am by yosler Reason: 1
Hi,
I just took apart my rc helicopter S022 (I lost the remote). Just for a start, I was trying to simply power the motor through Arduino.
The motor has no specs, so I don't know what resistor (if any) I should use because I don't want to burn out the motor.
The motor has just 2 wires - red and black. I connected the red to digital pin 6 and the black to ground.
But do I control the motor through analog or digital write? How do I control how many Volts are applied?
When I tried analogWrite(motorPin, 150) nothing happened except for something that sounded close to a quiet beep (like voltage was applied), but no motor movement.
What's wrong?
Thanks. Any help is appreciated.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

be80be

You dont like your uno do you you can't run the motor from a pin off the uno
You need more power or even volts that the pin can output 40ma 5 volt max that motor may us over a AMP.

You'll need a transistor as switch http://playground.arduino.cc/Main/DCMotorControl

yosler

I have a transistor. I also have a 9V battery ready to be connected to Vin.
What do I need to power my transistor and make it work?
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

You say you don't know the specs of the motor. Do you know what battery was used with it before?
Good luck, Jack

yosler

7.4V battery that says:

7.4V
702540K
-031

Not sure what battery that is. It looks two cell.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

What do you need that motor to do for you? Fly, or ?? If you want to to fly you may need the full voltage, and amps, but for most other uses, the 5 volt would probably be just fine.
Good luck, Jack

yosler

For right now just get it to spin (to a desired speed).
The image at the following link looks like the one I'm using (but the words on the front look wrong and there the back on mine is the same on both sides).
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

yosler

#7
Aug 12, 2013, 04:26 am Last Edit: Aug 12, 2013, 04:29 am by yosler Reason: 1
Here's a better link:
http://www.rchelicoptershop.com/rc-helicopter-parts/toy-helicopter-parts/syma-s022-parts/syma-li-po-battery-for-s022-chinook.html
That's the battery I have. Any more info about it would be great.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

Ok,
Quote
I have a transistor.

Is it npn or pnp, or better yet what is it? TIP120, or what?
If you hook the motor across the 9 volt battery, does it spin as you would expect?
Do you also have a diode we can place across the motor to help protect the transistor?
We are just about there.

Once we get all these parts in place, what do you want the arduino to do first, Turn the motor on and off ever second. (Just first test?). Sounds good. Use the blink example program (have you got that working yet?), then we can change the output pin to control the transistor. (I am hoping that is an NPN transistor). Let us know .
It's getting sorta late here. If you don't hear back, that means I have turned in for the night, and will be back on tomorrow.

Good luck, Jack

yosler

I'm not sure, but I got the canaKit for arduino (sparkfun inventor's kit) and am right now using the online manual for the motors on page 67 of the manual:
http://www.canakit.com/Media/Manuals/SIK-Manual.pdf
One problem is I'm missing my diode (for right now I can't find it).
Without the diode, the gear on my motor moves a drop, but it I think is too much torque to turn the bigger gear which turns the propeller.

Update: I connected the + and - pins from my 7.4V battery to the breadboard circuit. Pin #6 was connected to 330 Ohm resistor to the middle pin of the transistor. The 7.4 V were connected to the motor, and the ground of the motor was connected to the collector. The emitter was connected to ground of the battery. When I turned it on, the motor turned fast. I'm worried something will burn out if I apply to many amps or something.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

Here is a link that has a video that really explains a lot of what you are looking for. I hope it helps.
http://www.jeremyblum.com/2011/01/31/arduino-tutorial-5-motors-and-transistors/
Good luck, Jack

yosler

I found 4 of these things on my circuit board of the helicopter. By the letters and numbers on it, I found the product online:
http://pdf1.alldatasheet.com/datasheet-pdf/view/85382/FAIRCHILD/FDD8896.html
So it's a semiconductor resistor (I believe).
So what does all of that data mean? Am I able to use my 40V 200 milliamp resistor? The semiconductor's datasheet says 30V 94A 5.7 milliohms.
There are normal yet strange results when I make my motor spin but it's hard to explain:
1) Doesn't seem like I can set the speed.
2) When I tried a for loop for speeding up and down, it didn't work.
3) When I press reset when the motor is spinning to restart, the motor just goes faster (I assume it's a build up of power in the resistor)
4) Sometimes, the motor just makes a very quiet noise as if there's voltage of some sort applied, but not enough to spin the motor
5) When that happens (not sure if this is always true), if I nudge the gear/propeller, the motor starts spinning.
What does this all mean? How can I fix it (without buying extra parts other than what's in my kit)?
Thanks.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

Please give us a schematic. If you have a camera, you can draw it on paper, and take a photo.
Good luck, Jack

yosler

A schematic of what?
I tried following the lines on the circuit board but there's no lines to follow.
Do you want a schematic of the breadboard circuit I made?
My father knows all about current, circuits, resistors, voltage, transistors, semiconductors etc. (mechanical engineer) so he's telling me about voltage dividers and how to make one.
See attachment for schematic of my circuit.
I'm 13 and I'll frequently be wordy, not writing to the point.
But don't worry, I know somethings about electronics.

jack wp

Ok. Looks like your hardware is hooked up alright.
Now you want to try to make the arduino control the motor.
Try the blink program, and use your pin D9 rather, or in additional to the pin D13

That should make the motor turn on and off.
About my bed time. I will be back tomorrow.
Good luck, Jack

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