Buttons

The buttons API allows you to read the state of the buttons on a badge. This API encapsulates the drivers for different button types.

Badge support

This API is currently supported on the following badges:

• SHA2017
• Hackerhotel 2019
• Disobey 2019
• CampZone 2019
• Disobey 2020
• Fri3dcamp 2018

Support for GPIO buttons and touch-buttons via the MPR121 touch controller IC are supported. Touch buttons using the touch button features of the ESP32 can not be used (yet).

Reference

Command	Parameters	Description
attach	button, callback function	Attach a callback to a button
detach	button	Detach a callback from a button
value	button	Get the current value of a button
getCallback	button	Get the current callback of a button
pushMapping	[mapping]	Switch to a new button mapping
popMapping	none	Switch back to the previous button mapping
rotate	degrees	Adapt the button layout to an orientation. Accepts 0, 90, 180 and 270 as values.

Button availability per badge

Name	SHA2017	Hackerhotel 2019	Disobey 2019	CampZone 2019	Disobey 2020	Fri3dCamp 2018	OpenHardwareSummit 2018
A	Yes	Yes	Yes	Yes	Yes
B	Yes	Yes	Yes	Yes	Yes
SELECT	Yes	Yes	No	No	Yes
START	Yes	Yes	No	No	Yes
UP	Yes	Yes	Yes	Yes	Yes
DOWN	Yes	Yes	Yes	Yes	Yes
LEFT	Yes	Yes	Yes	Yes	Yes
RIGHT	Yes	Yes	Yes	Yes	Yes

Default callback per button

Name	SHA2017	Hackerhotel 2019	Disobey 2019	CampZone 2019	Disobey 2020	Fri3dCamp 2018	OpenHardwareSummit 2018
A
B			Exit app	Exit app
SELECT
START	Exit app	Exit app			Exit app
UP
DOWN
LEFT
RIGHT

Callback implementation:

to use the buttons, you need to implement a callback function:

import buttons, display # Imports 2 libraries to use the buttons, the display library, as well as the buttons library
def on_action_btn(pressed): # Defines a function on_action_btn with the required parameter pressed
    if pressed: # Uses an if statement to check if the button has been pressed
        display.drawFill(display.BLACK) # If the button is pressed, sets the screen to black
        display.drawText(10,10,"Hack The Planet!!!", display.GREEN, "roboto_regular18") # Draws text if the button is pressed
        display.flush() # Flushes the screen to draw the text and color onto the screen
buttons.attach(buttons.BTN_A, on_action_btn) # Assigns the function on_action_btn to the A button