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This is a good product build. I am amazingly impressed, yet I was hoping for alittle clarification as to which motors are conected to which analog inputs on the motor shield for the example code included?
Control an OWI Robotic Arm with Arduino
With the DC Cable how many voltage you used for the arduino?
Yep, you have nearly 180 degrees for z-axis, thus a wider arm movement. I tried to fit an optical sensor inside the motor itself, but it's too small to be abe to fit mine...
Actually, a bit more like a servo, which also has internal pots.
Nice. The Meccano brackets are a lot more rigid. And I guess the feet are spread farther apart than the limits of the base rotation?. And it looks a bit tidier and more elegant. - mkinoma
Ok thank you good explanation in a sense is this getting a motor to behave a bit more liker a stepper motor then ? - DavidB552
The motor controller cannot know how far the motors have turned the joint; even if it knows that running it for 2.3 seconds moves it by x degrees, there are too many factors that can mess up the timing. The pots will return distinct voltage values for every angle, consistently. For example, when the elbow is at some specific position, say about a third of the way through its travel, the pot will read, say, 1.6523443 volts or something like that. So if the controller is told "drive this motor forward until its pot returns 1.65 volts" it will stop at about the same angle every time. - mkinoma
According to the manufacturer (http://www.owirobot.com/robotic-arm-edge-1/) each 3V motor runs at 255mA at full tilt -- with no load. And there are five motors. Just being installed in the robot means there's a load, and it will go higher, all the way to the listed "stall current" of over 3 amps. The design is such that the motors cannot continuously stall in this robot, but still -- no microcontroller can deliver that directly even for a split second. You will definitely need a motor controller. I don't even think relays, transistors or MOSFETs will work because you've got to be able to reverse the polarity. By the time you've added all the circuitry to support it you've pretty much built a motor controller, so probably better to just buy one straight away. - mkinoma
How exactly is this powered? I was intending on plugging the ardiono into my USB port and jsut using that, but I'm worried there won't be enough current. Could someone please plainly explain how to power everything (shield, arduino and motors)? I'm also worried the shield needs too high a voltage! And i read somewhere that these motors are only rated for around 3v :sThanks for any help! :)
Has anyone tried to use these flex sensors for feedback? https://www.sparkfun.com/products/10264
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