Programming

/*
  Sync UNIX Time with Computer and
  LCD Display with I2C on Arduino UN0
  Rough Draft 0.1  (needs improvements)
  Neo December 2019
  https://www.unix.com
*/

// Include Wire Library for I2C
#include <Wire.h>
// Include NewLiquidCrystal Library for I2C
#include <LiquidCrystal_I2C.h>
#include <Time.h>
#include <TimeLib.h>

#define TIME_MSG_LEN 11 // time sync to PC is HEADER followed by Unix time_t as ten ASCII digits
#define TIME_HEADER 'T' // Header tag for serial time sync message
#define TIME_REQUEST 7  // ASCII bell character requests a time sync message
#define DEBUG_SKETCH false
// Define LCD pinout
const int en = 2, rw = 1, rs = 0, d4 = 4, d5 = 5, d6 = 6, d7 = 7, bl = 3;
// can be any integer greater than zero and less than recent unix time
const int time_int = 1000;
// Define I2C Address - change if reqiuired
const int i2c_addr = 0x27;
String s;
bool flag = true;
time_t t = now();
LiquidCrystal_I2C lcd(i2c_addr, en, rw, rs, d4, d5, d6, d7, bl, POSITIVE);
void setup()
{
    Serial.begin(9600);
    Wire.begin();
    time_t t = now();
    lcd.begin(16, 2);
    lcd.clear();
}

void loop()
{
    lcd.clear();
    int count = 0;
    if (Serial.available() and flag)
    {
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Serial OK");
        count = processSyncMessage();
        if (DEBUG_SKETCH)
        {
               Serial.println("Serial Available: " + count);
        }
        if (count > time_int)
            flag = false;
    }

    lcd.setCursor(0, 0);
    if (timeStatus() == timeNotSet)
    {
        if (flag)
        {
            Serial.println("waiting for sync message");
            lcd.print("Arduino Time:");
        }
    }
    else
    {

        lcd.print("Unix Time:");
        if (DEBUG_SKETCH)
        {
            Serial.println("Time Synced");
        }
    }
    t = now();
    s = String(t);
    if (s != '0')
    {
        lcd.setCursor(0, 1);
        lcd.print(t);
        lcd.print(" secs");
    }
    Serial.println(s);
    delay(1000);
    lcd.clear();
}

int processSyncMessage()
{
    while (Serial.available() >= TIME_MSG_LEN)
    { // time message consists of header & 10 ASCII digits
        char c = Serial.read();
        int count = 0;
        Serial.print(c);
        time_t pctime = 0;
        if (c == TIME_HEADER)
        {
            for (int i = 0; i < TIME_MSG_LEN - 1; i++)
            {
                c = Serial.read();
                if (c >= '0' && c <= '9')
                {
                    Serial.print(c);
                    count++;
                    pctime = (10 * pctime) + (c - '0'); // convert digits to a number
                }
            }
            Serial.print("\n");
            if (DEBUG_SKETCH)
            {
                Serial.write(pctime + "\n");
                Serial.println(pctime);
            }
            setTime(pctime); // Sync Arduino clock to the time received on the serial port
        }
        return count;
    }
}

# -----------------------------------------------------------
# Sync Unix Time with Arduino Initial Draft 0.1
# Written on macOS, tested with Python 2.7.16
# Neo, December 2019
# This code needs refinement to be more general
# I will improve this code later when I need to use it in an Arduino project
# For now, it works "OK" and serves it purpose
# Feel free to improve, modify as you like.
# -----------------------------------------------------------
import serial
import time

ser = serial.Serial(
    port='/dev/cu.usbserial-40',  #change this for your device
    baudrate=9600,
    parity=serial.PARITY_NONE,
    stopbits=serial.STOPBITS_ONE,
    bytesize=serial.EIGHTBITS,
    timeout=0)

print("connected to: " + ser.portstr)

# this will store the line
line = []
ux = 0
a = False
debugScript = False
offset = 2 .  #adjust this time offset (in seconds) to account for various time delays in script and transferring via the serial port, etc. to insure the Arduino is in closer sync to the computer
time_int = 1000  # this can be any number greater than zero and less than recent unix time
count = 0
while True:
    if debugScript:
        print(str(int(time.time())))
    for c in ser.read():
        if not a:
            if ux < time_int:
                ser.write("T")
                ux = int(time.time())+offset
                ser.write(str(ux))
                ser.write("\n")
                ser.flush()
                if debugScript:
                    print("unixtime: " + str(ux))
        line.append(c)
        count += 1
        if c == '\n':
            print("Line("+str(count)+"): " + ''.join(line))
            x = int(time.time())+offset
            print("time("+str(count)+"): " + str(x) + "\n")
            line = []
            a = True
            break
ser.close()

macos# crontab -l
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.6hwbckCLEy installed on Tue Dec 24 14:09:49 2019)
# (Cron version -- $FreeBSD: src/usr.sbin/cron/crontab/crontab.c,v 1.24 2006/09/03 17:52:19 ru Exp $)
* * * * * /usr/bin/python /usr/local/bin/neo/checkArduino.py

macos# cat /usr/local/bin/neo/checkArduino.py
import os.path
from os import path

device = '/dev/cu.usbserial-40'
syncscript = '/usr/local/bin/neo/sync_unixtime.py'
if path.exists(device):
   execfile(syncscript)

macOS:LaunchDaemons# ls -l *neo*
-rw-r--r--  1 root  wheel  453 Dec 24 15:30 com.neo.startup.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>Label</key>
        <string>com.neo.startup</string>
        <key>ProgramArguments</key>
        <array>
                <string>/usr/bin/python</string>
                <string>/usr/local/bin/neo/checkArduino.py</string>
        </array>
        <key>StartInterval</key>
        <integer>1</integer>
</dict>
</plist>

macOS:LaunchDaemons# launchctl load -w /Library/LaunchDaemons/com.neo.startup.plist