Buttons

[lmoss30]

The buttons on the flight Astros Pis how are they wired, do they come of the sense hat direct?sorry if this has been asked before

[jdb]

There is an interstitial board fitted to the AstroPi flight models that brings 6 GPIOs through some hardware debounce to the case-mounted buttons.

The button-GPIO mapping is as follows:
UP = 26
DOWN = 13
LEFT = 20
RIGHT = 19
A = 16
B = 21

We actually use a gpio-keys devicetree overlay to implement these buttons. They map to keyboard keys u / d / l / r / a / b respectively, which allows us to use Linux standard event drivers to respond to button presses.

The SenseHAT joystick maps the canonical direction keys (Up/Down/Left/Right) and centre push (Enter) in the same fashion.

[dliloch]

I have a python script in a @reboot user crontab. The pygame command to look for a down joystick works fine when running in a command window but not in crontab.(if event.type == pygame.KEYDOWN). so could I test gpio pin 13 instead? I need someway to have the sensehat run a shutdown command since it will be run headless.. If I just pull the power I am worried that I will corrupt the sd card.
thanks...

[AndersM]

I need someway to have the sensehat run a shutdown command since it will be run headless

Have you tried this new stick class?

EDIT:
Made a test script called stickpoweroff.py based on the new class:

Code: Select all

from sense_hat import SenseStick
import os

stick = SenseStick()

for event in stick:
        if event.key == stick.KEY_ENTER :
            os.system("poweroff")
        elif event.key == stick.KEY_UP :
            os.system("reboot")

And ran it by adding this line in rc.local

Code: Select all

python3 /home/pi/stickpoweroff.py &

It seems to work.

[dliloch]

thanks so much! It worked!
-don

[AndersM]

Hm ... how do I turn it on again?

The lack of on/off switch is a bit annoying.