• INTRODUCTION
• INTRODUCTION
• GETTING STARTED
• GETTING STARTED
• STARTER COMMANDS
• USING
• PEN COMMANDS
• PEN COLORS
• TRY TURTLE ART
• TURTLE ART LETTERS
• REPEATING COMMANDS
• NUMBERS AND COMMANDS
• SHAPES AND SPECTRUM
• SENSORS
• APPENDICES
• CREDITS

SENSORS

Turtle Art can read the keyboard, camera and microphone inputs. The program below reads the microphone and displays the pitch.

External Sensors

Turtle Art can also measure the voltage and resistance of a device plugged in to an XO laptop microphone socket but take care not to exceed the allowable input voltage.

The XO1 allowable input is -0.5V to 5V. Inputs outside this range will cause excessive current and damage. Even a single 1.5V battery can cause damage if connected reverse polarity.

The XO1.5 allowable input is -6V to +9V . 

If applying an external voltage to the XO1, it is highly recommended that test leads be made up with a microphone plug and an inbuilt series resistor. 680 ohms is the suggested resistor value, it gives a reasonable input range while still allowing the use of the full resistance range of the XO1. 

Voltage measurement range

XO-1 DC 0.4V to 1.85V

XO-1.5 0.17V - 3.0V

Resistance measurement range

XO-1 750 ohms to 14k ohms

XO-1.5 2k ohms to open circuit

Use resistance sensing to measure water conductivity.

For more examples of using Turtle Art with sensors, see http://wiki.sugarlabs.org/go/Activities/TurtleArt/Using_Turtle_Art_Sensors