DavesCodeMusings

Make a time series database using SQLite.

Time series DBs are useful for storing data taken from the environment. For example,
weather readings from a station at fifteen minute intervals throughout the day.

Rather than using a popular, but more resource intensive purpose built time series
database for your small scale project, you can just as easily use good old SQLite.

DavesCodeMusings

# Sample Eclipse Mosquitto config with MQTT Secure and MQTT Secure Websockets.
# You need to provide the server.crt, server.key, and ca-certificates.crt

# Global Options
allow_anonymous true
persistence true
persistence_location /mosquitto/data/
log_dest stdout

# Standard MQTT

DavesCodeMusings

from machine import Pin, SoftI2C, Timer
from ssd1306 import SSD1306_I2C
from network import WLAN, STA_IF
from time import ticks_diff, ticks_ms
from config import WIFI_NAME, WIFI_PASS, WIFI_TIMEOUT

BOOT_BUTTON_GPIO = 9  # ESP32 is 0, ESP32-C3 is 9
SCREEN_TIMEOUT = 30   # Seconds before blanking OLED

i2c = SoftI2C(scl=Pin(4), sda=Pin(5))

DavesCodeMusings

#!/bin/sh

# Create initial directories and files for home automation stack.

BASE_DIR=$(pwd)
ESPHOME_DIR=$BASE_DIR/esphome
HASS_DIR=$BASE_DIR/hass
MOSQUITTO_DIR=$BASE_DIR/mosquitto
NODE_RED_DIR=$BASE_DIR/node-red

DavesCodeMusings

This shell script will back up files from remote systems as well as local
using rsync. Default behavior is to prune any backups older than 90 days,
except for Sundays. This results in daily copies for up to 90 days and weekly
copies for anything older.

Sample crontab entries to back up multiple hosts on a schedule:
0       6       *       *       *       /media/backup/backup.sh lorum.home
0       7       *       *       *       /media/backup/backup.sh ipsum.home
0       8       *       *       *       /media/backup/backup.sh dolor.home

DavesCodeMusings

class GapBuffer:
    def __init__(self, size, prefill=None):
        self._buffer = bytearray(size)
        self._gap_start = 0                # first element of gap
        self._gap_end = len(self._buffer)  # first element after gap
        if prefill != None:
            prefill_end = len(prefill) if (len(prefill) <= size) else size
            self._buffer[0:prefill_end] = prefill[0:prefill_end]
            self._gap_start = len(prefill)

DavesCodeMusings

# Example of using uasyncio to run a web server.
# The server does nothing but echo back what was sent to it.
# But the point here is to demonstrate the use of uasyncio, callbacks,
# and the mixing of async and regular (synchronous) functions.

import uasyncio

# This is a synchronous function that gets called from inside the async function.
def create_http_response(body):
    res_lines = []

DavesCodeMusings

# After booting, the BOOT button attached to GPIO 0 is available to use as a regular input for your program.
# GPIO 9 is used for BOOT on the ESP32-C3. Check the Espressif docs for other ESP variations.
from machine import Pin

p0 = Pin(0, Pin.IN, Pin.PULL_UP)  # Normal state is logic high, pressing the button will pull it low.
pressed = False  # Flag to track if button was pressed.

def irq_handler(pin):
    global pressed
    pressed = True

DavesCodeMusings

# Enable MicroPython WebREPL (Console over Websockets)
from machine import Pin, SoftI2C
from ssd1306 import SSD1306_I2C
from network import WLAN, STA_IF
from webrepl import start
from netcfg import AP_NAME, AP_PASS, WEBREPL_PASS
from ubinascii import a2b_base64
from time import sleep

i2c = SoftI2C(scl=Pin(4), sda=Pin(5))  # Wemos board with built-in OLED uses pins 4 (clock) & 5 (data)

DavesCodeMusings

#!/usr/bin/env node

let _console_debug = console.debug
console.debug = function(message) {
  if (debug) {
    _console_debug.apply(console, arguments)
  }
}

let debug = true