pico-epaper/storage.py

import machine
import sdcard
import uos
import random

class Storage:
    def __init__(self):
        self.cs = machine.Pin(17, machine.Pin.OUT)
        self.spi = machine.SPI(0,
                              baudrate=1000000,
                              polarity=0,
                              phase=0,
                              bits=8,
                              firstbit=machine.SPI.MSB,
                              sck=machine.Pin(18),
                              mosi=machine.Pin(19),
                              miso=machine.Pin(16))
        self.sd = None
        self.vfs = None
        self.sd_path = "/sd"
    def mount(self):
        self.sd = sdcard.SDCard(self.spi, self.cs)
        self.vfs = uos.VfsFat(self.sd)
        uos.mount(self.vfs, self.sd_path)
    def umount(self):
        uos.umount(self.sd_path)
    def get_root_path(self):
        return self.sd_path
    

def load_joke(root):
    filename = root + "/jokes.json"
    num_lines = sum(1 for line in open(filename))
    with open(filename, mode="r") as f:
        joke = None
        start_pattern = "\"joke\": \""
        end_pattern = "\""
        for i in range(random.randrange(num_lines)):
            line = f.readline()
        for i in range(10):
            line = f.readline()
            joke_start = line.find(start_pattern)
            joke_end = line.rfind(end_pattern)
            if joke_start >= 0 and joke_end >= 0:
                joke = line[joke_start+len(start_pattern):joke_end]
                return joke
    return None