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Topic: radio shack motor shield docs (Read 5351 times) previous topic - next topic

legoaceking

I just bought an Arduino motor shield at Radio Shack but I can't locate the docs or example code for this on the arduino site
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PaulS

Maybe you should ask Radio Shack for the documentation. They took your money. They should provide documentation.

zoomkat

You can read some of the review comments at the below link for possible help.

http://www.radioshack.com/product/index.jsp?productId=12333768
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.


Maybe you should ask Radio Shack for the documentation. They took your money. They should provide documentation.

Actually this is an Arduino product, and radio shack is just re-selling it. So Arduino is responsible and they should have documentation for their products including example code.
If Arduino is going to sell electronics for prototyping they need to provide documentation, otherwise it is false advertisement and a complete waste of time to offer the product for sale.

PaulS

Quote
So Arduino is responsible and they should have documentation for their products

You mean like this:
http://arduino.cc/en/Main/ArduinoMotorShieldR3

What example code do you need?

legoaceking

i have tryed http://arduino.cc/en/Main/ArduinoMotorShieldR3 but it dose not have example code do drive a dc moter
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PaulS

Quote
but it dose not have example code do drive a dc moter

What code do you need? Set the direction pin HIGH to go one way. Set it LOW to go the other way. Set the speed using analogWrite() with some value between 0 (slowest) and 255 (fastest).

TeslaFan

#7
Dec 06, 2011, 06:35 am Last Edit: Dec 06, 2011, 07:03 am by TeslaFan Reason: 1
I have to agree with the OP (Legoaceking) here. If Arduino is going to release reference schematics, then they should be putting simple code examples in the web pages for those reference schematics.

Legoaceking:

Here's the basics.

The Motor shield will drive 2 brushed DC motors. There are 2 control signals per motor. The control signals are DIRECTION and SPEED.

DIRECTION is a digital output port set to "1" for one direction, and "0" for the other. SPEED is also a digital output port, but it's special. It's set to high only for a percentage of the time. That percentage is set by a function called analogWrite().

analogWrite() doesn't actually output an analog signal. What it does is set up a digital output bit to be high for a percentage of the total time. For more info, check the reference info here: http://www.arduino.cc/en/Reference/HomePage PRO TIP: Googling "Arduino Reference" will get you right to it.

The Arduino motor shield uses 4 digital output ports to control the 2 motors. They are assigned to these ports:

Motor A:
Direction: port 13
Speed: port 3

Motor B:
Direction: port 12
Speed: port 11

Why they chose these ports I'll never know. They directly interfere with the primary communication channel of the Arduino... the SPI system. This is the system that ALL the major communication shields use. As such, you cannot use the motor shield along with a WiFly shield, a USB Host shield, an Ethernet shield, or a micro-SD shield. All of these use digital ports 10, 11, 12, and 13. Which are the digital ports used by the SPI system.

So. To use the motor shield to run a motor, you set a direction and a speed by setting the ports for that motor.

Like this:

First. Set the pin mode of the ports you need to use.

For Motor A:
pinMode(13,OUTPUT);
pinMode(3,OUTPUT);

For Motor B:
pinMode(12,OUTPUT);
pinMode(11,OUTPUT);


To set motor A to 50% speed going in direction 1:
digitalWrite(13,1);
analogWrite(3,128);

Hmm. Which direction is "Direction 1"? Try it and see! If it's the wrong way, just reverse the motor wires.

To set motor A at zero speed: (The direction port really doesn't matter with 0 speed.)
digitalWrite(13,1);
analogWrite(3,0);

To set motor A at max speed:
digitalWrite(13,1);
analogWrite(3,255);

As you can see, the range of the speed you can set is 0 to 255.

To set motor B at zero speed: (The direction port really doesn't matter with 0 speed.)
digitalWrite(12,1);
analogWrite(11,0);

To set motor B at max speed:
digitalWrite(12,1);
analogWrite(11,255);
Linux and Arduino, two great things that go great together!
http://www.roboticcore.com


Quote
So Arduino is responsible and they should have documentation for their products

You mean like this:
http://arduino.cc/en/Main/ArduinoMotorShieldR3

What example code do you need?


Perhaps something like this? http://www.ladyada.net/make/mshield/
with code that is maintained like this: https://github.com/adafruit/Adafruit-Motor-Shield-library
with information on how to install Arduino Libraires for those of us who might not have done it before or ... since it was changed, and most likely will change again. Like this: http://www.ladyada.net/library/arduino/libraries.html

So I guess the moral of the story for me is, I should have just purchased the Adafruit one, and I do suggest that for all of those people out there that have mistakenly purchased the Arduino Motor Shield r3 thinking that it was going to be of quality work, or at least comparable to what Adafruit has on the market.

Hopefully the documentation will come, and if not hopefully they will provide some vehicle for the community to develop for it, ie. Wiki

Forbesg

I too just purchased a motor shield R3 from Radio Shack.  If I had bothered to research the unit, I would have bought the Adafrut unit.  But alas RS is walking distance and timing was important.  It is going back today and I am ordering an Adafrut unit.  I think the R4 was designed for a specific project and not for general use.  Looking forward to hearing anyone else's experience with this or any other Arduino products purchased from RS.  The store personnel are clueless as far as technical questions are concerned.  Radio Shack take note,
hire technically competent people if your are going to serve the electronics hobby market.

zoomkat

Quote
Radio Shack take note, hire technically competent people if your are going to serve the electronics hobby market.


In the electronics hobby market today, you are generally expected to know what you are doing, not necessarily depend on the person behind the counter. If you don't understand what you are going to buy, then don't buy. It is amazing that radio shack still carrys any electronic hobby parts.

Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

PaulS

Quote
It is amazing that radio shack still carrys any electronic hobby parts.

I think Radio Shack is trying to get back into the hobby/electronics filed. They aren't doing so well selling phones. The problem is that at the store level, the employees know how to sell phones, If you can get their attention at all. As much as I'd like to see the venture with Arduino succeed, I doubt that it will.

dewy721

Does anybody know if the Radio Shack "Arduino Motor Shield R3" board has TWI/I2C control or is it just a pass through connection? If it does: How might one find the I2C ID for this device?

ajofscott

The TWI is a pass through, as do analog pins 2 and 3, 0 and 1 are used by the current sense amps on the Motor3 board. The pin destination is in the silkscreen by the applicable connector.

ajofscott

BTW the link to the docs should have been on the customer reviews page at Radioshack, as I took the effort to post it in a review after I bought mine. Late in the day I bought mine Arduino finally got the reference pages online for the motor3.

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