Motors! WK 6
Faith and I met bright and early on Monday morning (Maker Mondays!) and completed Experiments 8 and 9 fairly quickly. Maybe we can blame our Monday brains for a couple of missteps. With Experiment 8, we forgot to put spinner on the motor at first. We also had a moment of confusion when a book diagram from another Arduino kit was different from online diagram. We followed the online version to success.
Experiment 8: Using a Servo Motor
https://drive.google.com/file/d/0BwDIPYofjRLbaXVBbXFfMXlMRUlmaTA3Ul82MEVPTTdQV0Jr/view?usp=sharing
Experiment 9: Driving a Motor with an H-Bridge
https://drive.google.com/file/d/0BwDIPYofjRLbWFU5c3gyTWdTWTZaRDJQSUdSMGhtVS03M2VV/view?usp=sharing
Experiment 10: Controlling a Motor with Inputs
Talk about attention to detail! Lots of connections on this one, and I wonder how anyone with large hands could wire this. We could control the speed well through the potentiometer. The button controlled the motor’s direction inconsistently, but worked best when we pressed down on it, so maybe it was a connection problem. I was concerned about the caution in the directions (below) and wasn't sure how to keep the MV isolated from other circuitry. I guess I did it ok - no RedBoard damage occurred.
CAUTION: You will be using voltage that may be higher than the limit of the circuitry on your RedBoard allows! Make sure you keep motor voltage (MV) isolated from other circuitry! Accidentally using MV to power other circuitry may cause irreparable damage to your RedBoard!
https://drive.google.com/open?id=0BwDIPYofjRLbZF82Z0JwVTE0OE5mck8yQWpoUmFVZ3lZai0w
Experiment 11: Reading Serial Data
When we first set up the boards the LED did not light. We repositioned the 4 pin LED (per the troubleshooting tip, and the light turned green (not purple).
We went back to the diagram and realized that we had forgotten the second red wire - then we were successful!
More About Motors
Faith's post about building a simple wind generator would fit well in an engineering unit I teach third graders each year. After exploring mechanical engineering, weather, and wind, students design and create sailboats and windmills that catch the wind and carry a weight load. The task described in Faith's post uses wind to power a motor and generate enough electricity to light an LED. I like the idea of extending my existing unit with electricity and circuitry concepts and I think this would excite students as well.. They would learn that this simple wind generator is a model for wind turbines used to generate electricity around the world. Students could use an iterative design process by trying materials other than a cup to construct something they think will best utilize the wind to yield the most rotations per second.
The post had clear directions that would help keep the experiment simple. In addition to the step by step making of the unit, they stated, "Twist each leg of the LED through a different terminal on the back of the motor. The correct orientation of the LED will depend on whether the blades spin clockwise or counterclockwise, so you will know if you need to switch it once you test the windmill. Slide your blade frame onto the shaft of the motor LEDs only work in one direction in a circuit.Depending on the torque of your motor and the intensity of your LED, it may be difficult to see the light turn on. Play around with different materials to find a combination that works for you and your wind source." I would make sure to do this myself first to really understand it. Depending on the group, I might precut some cups to minimize frustration for some students.
It sounds like attaching an LED to the back of the motor could potentially be tricky for students. "Your motor will output DC current, but it may be in the reverse of the direction your LED needs. If you have trouble getting the LED to light up, try switching the leads to make sure it’s connected in the correct orientation." Again, I'd definitely need to play around with it first.
Advanced concepts for students who are ready could include adding other motors and LEDs, hookup wires and, alligator clip leads. Could they design a stand that will turn into the wind like some wind generators do?
As I write this I'm wondering if I would have enough time to add an electrical engineering piece to the original project. Maybe making wind generators could be a follow-up task to the unit for students who are motivated to pursue it.
Experiment 8: Using a Servo Motor
https://drive.google.com/file/d/0BwDIPYofjRLbaXVBbXFfMXlMRUlmaTA3Ul82MEVPTTdQV0Jr/view?usp=sharing
Then, with Experiment 9, it took us a while to find the H-Bridge until we realized it had a cover that was disguising it.
https://drive.google.com/file/d/0BwDIPYofjRLbWFU5c3gyTWdTWTZaRDJQSUdSMGhtVS03M2VV/view?usp=sharing
Experiment 10: Controlling a Motor with Inputs
Talk about attention to detail! Lots of connections on this one, and I wonder how anyone with large hands could wire this. We could control the speed well through the potentiometer. The button controlled the motor’s direction inconsistently, but worked best when we pressed down on it, so maybe it was a connection problem. I was concerned about the caution in the directions (below) and wasn't sure how to keep the MV isolated from other circuitry. I guess I did it ok - no RedBoard damage occurred.
CAUTION: You will be using voltage that may be higher than the limit of the circuitry on your RedBoard allows! Make sure you keep motor voltage (MV) isolated from other circuitry! Accidentally using MV to power other circuitry may cause irreparable damage to your RedBoard!
https://drive.google.com/open?id=0BwDIPYofjRLbZF82Z0JwVTE0OE5mck8yQWpoUmFVZ3lZai0w
Experiment 11: Reading Serial Data
When we first set up the boards the LED did not light. We repositioned the 4 pin LED (per the troubleshooting tip, and the light turned green (not purple).
We went back to the diagram and realized that we had forgotten the second red wire - then we were successful!
More About Motors
Faith's post about building a simple wind generator would fit well in an engineering unit I teach third graders each year. After exploring mechanical engineering, weather, and wind, students design and create sailboats and windmills that catch the wind and carry a weight load. The task described in Faith's post uses wind to power a motor and generate enough electricity to light an LED. I like the idea of extending my existing unit with electricity and circuitry concepts and I think this would excite students as well.. They would learn that this simple wind generator is a model for wind turbines used to generate electricity around the world. Students could use an iterative design process by trying materials other than a cup to construct something they think will best utilize the wind to yield the most rotations per second.
The post had clear directions that would help keep the experiment simple. In addition to the step by step making of the unit, they stated, "Twist each leg of the LED through a different terminal on the back of the motor. The correct orientation of the LED will depend on whether the blades spin clockwise or counterclockwise, so you will know if you need to switch it once you test the windmill. Slide your blade frame onto the shaft of the motor LEDs only work in one direction in a circuit.Depending on the torque of your motor and the intensity of your LED, it may be difficult to see the light turn on. Play around with different materials to find a combination that works for you and your wind source." I would make sure to do this myself first to really understand it. Depending on the group, I might precut some cups to minimize frustration for some students.
It sounds like attaching an LED to the back of the motor could potentially be tricky for students. "Your motor will output DC current, but it may be in the reverse of the direction your LED needs. If you have trouble getting the LED to light up, try switching the leads to make sure it’s connected in the correct orientation." Again, I'd definitely need to play around with it first.
Advanced concepts for students who are ready could include adding other motors and LEDs, hookup wires and, alligator clip leads. Could they design a stand that will turn into the wind like some wind generators do?
As I write this I'm wondering if I would have enough time to add an electrical engineering piece to the original project. Maybe making wind generators could be a follow-up task to the unit for students who are motivated to pursue it.
Love the connections to wind! Energy is such an important unit in a world that is looking more and more towards solutions for sustainability.
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