ROBOTC for IFI FIRST

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ROBOTC for IFI - FIRST

• Timothy Friez
• Class 3
• 1/29/08

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Outline for Tonight

• Questions from Last Week
• IR Board review
• Encoder Go Straight Demo
• Accelerometer Introduction
• Wireless Feedback via LEDs
• 10 minute break - Going to actually be 10
  minutes!
• Gyro Sensor
• Purpose
• How it works
• Testing and Developing a Program
• Questions

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ROBOTC for IFI Version 1.14

• New ROBOTC version
• Releasing tomorrow 1/30/08
• Has built in support for encoders, accelerometer,
  gyro sensor, OI LEDs and more!
• Make sure to upgrade!

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Any Questions from Last Week?
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IR Board Review

• Rule Clarification from Team Update 3
• 4 Signals Allows
• 4 Signals 4 actions
• Signals must repeat when the same button is
  pressed.
• The code we developed last meeting meets all of
  these requirements!

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Encoder Go Straight

• Last Weeks Notes
• Use Motors and Sensors Setup to configure our
  encoders
• Clear the encoders before using them
• Program Go straight using encoder feedback
• If left wheel lags behind, slow down right wheel
• If right wheel lags behind, slow down left wheel
• If both wheels are equal, go an equal speed.
• Use Three If statements

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Accelerometer

• The Dual-Axis Accelerometer (DAA) measures both
  vibration and gravity.
• It should be connected to two of the RC analog
  inputs.
• One to measure X-axis and one to measure Y-axis
  acceleration.

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Using Accelerometer with ROBOTC

• Connect to two analog inputs (analog inputs 2 and
  3 on our robot)
• Set Motors and Sensor Setup to Accelerometer.

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Using Accelerometer with ROBOTC

• Access values with
• SensorValuex_axis
• SensorValuey_axis
• Values will range from -200 to 200
• Scale is 100ths of a G
• So a value of 153 would be 1.53Gs
• Sensor will be at rest at or near zero.

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Accelerometer Demo
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Operator Interface LEDs

• 11 LEDs installed on Operator Interface
• 7 Green
• 4 Red
• User Controllable with ROBOTC

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Controlling the LEDs

• New ROBOTC function
• frcOILEDsLED true or false
• Examples
• frcOILEDsoiLEDPWM1_Green true
• Turns on PWM1 Green LED
• frcOILEDsoiLEDPWM1_Green false
• Turns off PWM1 Green LED

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LED Demo
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Gyro Sensor

• The Yaw Rate Gyro sensor is used to determine
  rotation.
• The output labeled T is for Twist or
  rotational velocity.
• The output labeled R is Relative Temperature.
• 80 degrees/sec resolution

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How to use with ROBOTC

• Connect to one analog input twist only
  (analog input 1 on our robot)
• Set Motors and Sensor Setup to Accelerometer.

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How to use with ROBOTC

• Access using the command
• SensorValuegyro
• Sensor will give back results in tenths of a
  degree.
• A reading of 900 is actually 90.0 degrees
• The sensor is automatically zeroed at the start
  of your program.

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Gyro Demo