Gyro circuit hack

By detecting these small changes gyros help stabilize the flight of the aircraft. Also, note that the acceleration or linear velocity of the aircraft does not affect the measurement of the gyro. Gyros only measure angular velocity. How does the MEMS gyro detect angular velocity? The gyroscope sensor within the MEMS is tiny between 1 to micrometers, the size of a human hair. When the gyro is rotated, a small resonating mass is shifted as the angular velocity changes.

This movement is converted into very low-current electrical signals that can be amplified and read by a host microcontroller. The primary hardware connections to use a gyro are power and a communication interface. As always, refer to the sensor datasheet for all of the information on specifications and example connections. Using these interfaces allow for an easy connection to a host microcontroller.

One limitation of a digital interface is max sample rate. I2C has a max sample rate of Hz. SPI, on the other hand, can have a much higher sample rate. Gyros with an analog interface represent rotational velocity by a varying voltage, usually between ground and the supply voltage.

An ADC on a microcontroller can be used to read the signal. Analog gyros can be less expensive and sometimes more accurate, depending on how you are reading the analog signal. MEMS gyros are generally low power devices. The supply voltage for gyros is usually 5V or less. Digital gyros can have selectable logic voltages or operate at the supply voltage.

For any digital interface, remember to connect 5V to 5V lines and 3. Also, gyros with digital interfaces can have low power and sleep modes that allow them to be used in battery powered applications. Sometimes this is an advantage over an analog gyro.

There are many specifications to consider when figuring out what type of gyro to use. Here are a few of the more important useful ones:. The measurement range, or full-scale range, is the maximum angular velocity that the gyro can read. Think about what you are measuring.

Do you need to measure the spin of a record player, which is very slow or a spinning wheel, which could be very fast? It determines how much the voltage changes for a given angular velocity. A good rule to remember: as the sensitivity increases, the range decreases. And really, MEMS chips are using the same principle to detect motion, just on a much smaller scale. Want the MEMS basics? They might be piezoelectric transformers instead of the usual electromagnetic type.

Please be kind and respectful to help make the comments section excellent. Comment Policy. This site uses Akismet to reduce spam. Then we convert the raw measurements to degrees per second.

Each variable is set equal to the raw output for each axis — gyro. Then we multiply each raw output by the conversion factor 8. Then we divide by to convert milli-degrees per second to degrees per second. Next we print the converted gyroscope readings to the serial monitor with a few Serial.

To display the readings in radians per second, change the argument in each Serial. Once the sketch is uploaded, open the serial monitor and you should see the reading from each gyroscope axis in degrees per second:. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Notify me of follow-up comments by email. Notify me of new posts by email. I agree to these terms. Previous Transistors: A Closer Look.

Next How to Use Interrupts on the Arduino. Related Posts. Anthony King on November 10, at pm. You seem to have Pi at 3. Scott Campbell on December 11, at am. Good eye! Thanks for the catch.