Finch Python Package Description

Description of Files

finch.py - Contains the Finch API functions for controlling Finch.

finchconnection.py - Contains low level functions for sending and receiving data over USB, used by finch.py.

hidapi32/64.dll, libhidapi.dylib, libhidapi32/64.so, libhidapipi.so - compiled C libraries used by finchconnection.py to scan for USB devices for the Finch robot and opens a connection. Windows uses the .dll files, OSX uses the .dylib files, and Linus uses the .so files.

testfinchfunctions.py - Example Python program.

Finch API

General

close

Closes the connection to the Finch

Usage: Call this when your program is exiting to cleanly close the Finch connection. This will shut off the motors and then send the Finch back to idle mode (color changing)

halt

Convenience function to shut off the Finch LED and finch motors

Usage: Call whenever you wish the Finch to stop moving and turn off its LED with one function call. Will not shut off the buzzer.

Outputs

led

Controls the Finch beak color.

Usage:

finch.led('#0000FF') # Hex triplet string
finch.led(0, 0, 255) # red, green, blue. 0-255 RGB values

wheels

Controls the power sent to the left and right wheels.

Usage: Values must range from -1.0 to 1.0 for each wheel.

finch.wheels(1.0, 1.0) # full forward
finch.wheels(-1.0, -1.0) # full reverse
finch.wheels(0.7, -0.3) # 70% forward on left wheel, 30% reverse on right wheel
finch.wheels(0.0, 0.0) # full stop

buzzer

Outputs sound over the Finch buzzer

Usage: Pass two parameters, duration in seconds followed by frequency in Hertz. Frequencies between 20 and 20,000 are audible.

finch.buzzer(0.5, 440). # plays 440 Hz note for 1⁄2 second

Note that this function does not delay program execution; to delay, use buzzer_with_delay. If two buzzer functions are called one after the other, only the second will play. For example, the following will only play a single 880 Hz note:

finch.buzzer(0.5, 220)
finch.buzzer(0.5, 880)

buzzer_with_delay

Outputs sound over the Finch buzzer, then blocks the program for delay equal to the duration of the note. Same usage as buzzer.

Sensors

temperature

Returns temperature in degrees Celcius.

Usage:

my_temperature = finch.temperature()

light

Returns the left and right light sensor readings, values range from 0.0 (dark) to 1.0 (bright)

Usage:

left_light_sensor, right_light_sensor = finch.light()

obstacle

Returns obstacle sensor readings, values are False for no obstacle, True for obstacle detected

Usage:

left_obstacle, right_obstacle = finch.obstacle()

acceleration

Returns (x, y, z, tap, shake).

Usage: x, y, and z, are the acceleration readings in units of G's, and range from -1.5 to 1.5. When the finch is horizontal, z is close to 1, x, y close to 0. When the finch stands on its tail, y, z are close to 0, x is close to -1. When the finch is held with its left wing down, x, z are close to 0, y is close to 1. tap, shake are boolean values; true if the corresponding event has happened.