UNIT 10
UNIT 10
Lesson 10 40 mins
Magnetometer is an in-built sensor on Pluto |
WHAT IS A MAGNETOMETER? (10 mins)
Magnetometer works on the lines of a compass. Students can be taught magnetometer using the analogy of a compass. |
A magnetometer is an instrument that measures magnetism—either magnetization of magnetic material like a ferromagnet, or the strength and, in some cases, directions of the magnetic field at a point in space.
Basically a magnetometer measures the earth’s magnetic field by using the hall effect or the magneto-resistive effect.
HOW DOES A MAGNETOMETER WORK? (15 mins)
The Hall Effect principle states that when a current carrying conductor is placed in a magnetic field, a voltage will be generated perpendicular to the direction of the magnetic field and the flow of current.
When a constant current is passed through a thin sheet of semiconducting material, the electrons would flow straight from one to the other side of the plate.
Now, if some magnetic field is brought near the plate, it would disturb the straight flow of the electrons and the electrons would get unevenly distributed on both sides. This would cause the formation of voltage across the plate.
That means if a Voltmeter is now connected across these two sides, it will get some voltage which depends on the magnetic field strength and its direction.
This principle is used to measure the Earth’s magnetic field which gives the heading of the drone.
COMPASS DRONE EXPERIMENT (PLUTO BLOCKS) (15 mins)
Trainer can demonstrate the working of magnetometer using this project. The drone will point north, east, south and west directions one after the other. |
Compasses have been used since ancient times to figure out directions. A typical compass points to the North direction. Using this project you can make your Pluto to point to North, East, South, West, or any other direction you want!
A properly Mag Calibrated drone when shows 0° as Yaw angle, it essentially points to the North direction. With every 90° added, it will change the direction. Thus, 90° will point to East, 180° will point to South and 270° will point to West.
If you set the desired Yaw angle of the drone to these angles, you will convert your Pluto into a compass! A suggestion, use different LEDs for different directions.
Directions with Yaw angles
Along with a few friends, try to guess the directions in a room with no sunlight. Then, use this project to verify the directions. The one with the correct guess wins!