init

README.md

@@ -1,3 +1,6 @@
-# rtctimestampbias
+# RTC timestamp bias
 
-Saving and comparing timestamps of the microcontroller's real time clock
+Saving and comparing timestamps of the microcontroller's real time clock
+
+- `rtctimestampbias.py` - main script for saving and comparing timestamps (`serial` and `csv` packages are required)
+- `rtctimestampbias.ino` - sample sketch for Arduino with DS1307RTC

rtctimestampbias.ino

@@ -0,0 +1,51 @@
+// RTC timestamp bias: Arduino with DS1307RTC example
+// https://gitlab.com/simplemicrocontrollers/rtctimestampbias
+#include <Thread.h>
+#include <DS1307RTC.h>
+
+// Time bias correction variables:
+int correctionBias = 0;                // Daily clock correction in seconds
+byte correctionHour = 3;               // 3AM - daily correction time
+long correctionCheck = 300000;
+bool correctionReady = true;
+Thread correctionThread = Thread();    // Time bias correction thread
+
+void setup() {
+  Serial.begin(9600);                  // Initializes the Serial connection @ 9600 baud for debug
+  while (!Serial);                     // Wait until Arduino Serial Monitor opens
+  setSyncProvider(RTC.get);            // The function to get the time from the RTC
+  if(timeStatus()!= timeSet) {         // Checking the time setting
+    Serial.println("Unable to sync with the RTC");
+  } else {
+//    Serial.println("RTC has set the system time");
+    Serial.println(now());             // Sending a timestamp to the serial port if a RTC is detected
+  }
+
+  // Time bias correction thread initialization:
+  correctionThread.onRun(correctionLoop);
+  correctionThread.setInterval(correctionCheck);
+}
+
+void loop() {
+  // Threads:
+  if (correctionThread.shouldRun())
+    correctionThread.run();
+}
+
+void correctionLoop() {
+  if (hour() == correctionHour) {
+    if (correctionReady) {
+      tmElements_t RTCtime;
+      RTC.read(RTCtime);
+      time_t RTCtimestamp;
+      RTCtimestamp = makeTime(RTCtime);
+      tmElements_t timeNew;
+      time_t newTimestamp = RTCtimestamp - correctionBias; // minus correctionBias seconds everyday
+      // if ((day() % 5) == 0) newTimestamp = newTimestamp - 1; // minus 1 sec every 5 days (-0.2sec everyday)
+      breakTime(newTimestamp, timeNew);
+      RTC.write(timeNew);
+      setSyncProvider(RTC.get);
+      correctionReady = false;
+    }
+  } else correctionReady = true;
+}

rtctimestampbias.py

@@ -0,0 +1,119 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# the following packages need to be installed via pip: 
+# serial, csv
+
+import serial.tools.list_ports
+import csv
+import time
+from datetime import datetime
+from optparse import OptionParser
+from sys import argv
+from os import path
+
+# RTC timestamp bias: saving and comparing timestamps
+# of the microcontroller's real time clock
+# https://gitlab.com/simplemicrocontrollers/rtctimestampbias
+
+version = "0.1"
+filename = "rtctimestampbias.csv"
+
+def ShowPorts(option, opt, value, parser):
+    number = 0
+    for port in ports:
+        if number > 0: print("---")
+        print(f"port {number}: {port.name}")
+        print(f"hwid: {port.hwid}")
+        print(f"desc: {port.description}")
+        number += 1
+
+def SaveByNumber(number):
+    SaveValue(ports[int(number)].device)
+
+def SaveByName(name):
+    for port in ports:
+        if port.name == name:
+            SaveValue(port.device)
+
+def SaveValue(device):
+    ser = serial.Serial(device, 9600)
+    response = ser.readline()
+    current_host_time = datetime.now()
+    decoded_response = int(response.decode('utf-8'))
+    ser.close()
+    print("Serial device timestamp:")
+    print(decoded_response)
+    hosttimestamp = int(round(current_host_time.timestamp()))
+    print("Host device timestamp:")
+    print(hosttimestamp)
+    csvdatarow = [[current_host_time, hosttimestamp, decoded_response]]
+    with open(filename, 'a') as csvfile:
+        csvwriter = csv.writer(csvfile)
+        for row in csvdatarow:
+            csvwriter.writerow(row)
+
+def CalculateCSVdata(option, opt, value, parser):
+    hostFirst = None
+    deviceFirst = None
+    hostLast = None
+    deviceLast = None
+    with open(filename, newline='') as csvfile:
+        spamreader = csv.reader(csvfile, delimiter=' ', quotechar='|')
+        rownumber = 0
+        for row in spamreader:
+            if rownumber == 0:
+                hostFirst = ', '.join(row).split(',')[2]
+                deviceFirst = ', '.join(row).split(',')[3]
+            hostLast = ', '.join(row).split(',')[2]
+            deviceLast = ', '.join(row).split(',')[3]
+            rownumber += 1
+    print(f"First timestamp of the host: {hostFirst}")
+    print(f"First timestamp of the device: {deviceFirst}")
+    print(f"Last timestamp of the host: {hostLast}")
+    print(f"Last timestamp of the device: {deviceLast}")
+    hostDiff = int(hostLast) - int(hostFirst)
+    deviceDiff = int(deviceLast) - int(deviceFirst)
+    totalDiff = deviceDiff - hostDiff
+    print(f"Host diff: {hostDiff}; device diff: {deviceDiff}; host/device total diff: {totalDiff}")
+    resultBias = (86400 / deviceDiff) * totalDiff
+    print(f"Resulting daily clock bias in seconds: {resultBias}")
+
+def CMDOptions():
+    class FormatedParser(OptionParser):
+        def format_epilog(self, formatter):
+            return self.epilog
+    usage = "usage: %prog [options]"
+    progname = path.basename(__file__)
+    epilog = ("".join(["Examples:\n  ",
+        progname, " -l\n  ",
+        progname, " -n 2\n  ",
+        progname, " -d ttyUSB0\n  ",
+        progname, " -c\n"]))
+    opts = FormatedParser(usage=usage, version="%prog " + version,
+                          epilog=epilog)
+    opts.add_option('-l', '--list', action="callback",
+                    callback=ShowPorts, help="show information about each port")
+    opts.add_option('-n', '--num', action="store", type="string",
+                    dest="num", metavar="number", default=False,
+                    help="save data by port number")
+    opts.add_option('-d', '--dev', action="store", type="string",
+                    dest="dev", metavar="name", default=False,
+                    help="save data by device name")
+    opts.add_option('-c', '--calc', action="callback",
+                    callback=CalculateCSVdata, help="calculate data from csv file")
+    options, value = opts.parse_args()
+    if options.num:
+        SaveByNumber(options.num)
+    if options.dev:
+        SaveByName(options.dev)
+    if len(argv[1:]) == 0:
+        print ("no argument given\n")
+        opts.print_help()
+
+if __name__ == "__main__":
+    ports = list(serial.tools.list_ports.comports())
+    try:
+        CMDOptions()
+    except KeyboardInterrupt:
+        exit()