Volumio PirateAudio Screensaver

#!/usr/bin/env python3

import os
import os.path
import ST7789 #v0.0.6
import sys
import signal
import RPi.GPIO as GPIO
import json
from signal import *
from time import sleep, strftime, gmtime # v.0.0.4
import time # v.0.0.4

display_state = "on"
timeout = 300
blanktime = time.time() + timeout

# get the path of the script
script_path = os.path.dirname(os.path.abspath(__file__))
# set script path as current directory
os.chdir(script_path)

# Create ST7789 LCD display class.
disp = ST7789.ST7789(
    height=240, #v0.0.6
    width=240, #v0.0.6
    rotation=90, # Needed to display the right way up on Pirate Audio
    port=0, # SPI port
    cs=1, # SPI port Chip-select channel
    dc=9, # BCM pin used for data/command
    backlight=13,
    spi_speed_hz=80 * 1000 * 1000,
    offset_left=0, #v0.0.6
    offset_top=0 #v0.0.6
)

# read json file (plugin values)
with open('/data/configuration/miscellanea/pirateaudio/config.json', 'r') as myfile:
    data = myfile.read()
obj = json.loads(data) # parse file

BUTTONS = [5, 6, 16, obj['gpio_ybutton']['value']]
# LABELS = ['A', 'B', 'X', 'Y']

GPIO.setmode(GPIO.BCM) # Set up RPi.GPIO with the "BCM" numbering scheme

def button_press(pin):
    global blanktime, timeout, display_state
    disp.set_backlight(True)
    display_state = "on"
    blanktime = time.time() + timeout

def setup_channel(channel):
    try:
        GPIO.setup(channel, GPIO.IN, GPIO.PUD_UP)
        GPIO.add_event_detect(channel, GPIO.FALLING, button_press, bouncetime=400)
    except (ValueError, RuntimeError) as e:
        print('ERROR:', e)

for x in BUTTONS:
    setup_channel(x)

while True:
    now = time.time()
    if now > blanktime and display_state == "on":
        display_state = "off"
        disp.set_backlight(False)
    sleep(1)