Morse Code 2 Short 1 Long
Berenguer Miramontes
Morse code is an old system of encoding messages that is used to send telegraphic information using signals and rhythm. In written communication, Morse code uses dots and dashes to represent a limited number of alphabet letters, numbers, punctuation and special characters of a given message. When messages are sent by sound, radio signals or light flashes, dots are short beeps or clicks or flashes, and dashes are longer ones. For example, Wikipedia written in Morse code is .-- .. -.- .. .--. . -.. .. .-
Morse code is named after Samuel Morse, who helped invent it. It is not used as much today as it was in the 19th and 20th centuries. Teletypewriters were invented in the early 20th century with their own codes and gradually replaced Morse code. Other types of technology that are easier to use for communication became even more common.
Some amateur radio operators still use Morse code to communicate and were previously required to learn and pass telegraphy exams to qualify their licenses. The requirements were lifted after 2003.[1]
There are three different symbols in Morse code; there's a short one, usually called 'dit', a long one, called 'dah', and the pause. A dah is three times as long as a dit, and the pause has the same length as the dit.
Today, Morse codes can be easily generated through smartphone applications or through a web application, which take text as input and outputs the Morse code in copyable text or downloadable audio form. Its usage as a method of sending secret messages has become obsolete in favor of more powerful encryption techniques provided by advanced modern computer machines.
The S.O.S as it is used today, was introduced by the Imperial German Marine in 1904. It was mandatory for all German ships starting in 1905. It was meant as a distress signal, and should be repeated until all other stations stopped sending. Afterwards the real message would be sent. Also, there is no pause between the characters.
At the time, the market was controlled by two companies; one was Telefunken, and the other was Marconi. Marconi was under British control, Telefunken was German. Marconi used CQD as a distress signal.
The people doing the communication were employees of either Marconi or Telefunken; they were not employed by the ships' owners. These operators were not allowed to answer calls sent by the competing company, which also included distress signals. As this was against the laws of the sea, a conference in Berlin decided to use the German distress signal internationally. This started in 1908. When the ship Republic sent a distress signal in 1909, it was still CQD, and the Titanic also sent CQD at first, in 1912.
The Global Maritime Distress and Safety System (GMDSS) is a satellite-based system that was introduced in 1999 to handle distress situations. It defines four different regions, three of which are covered by satellite. The fourth, which covers the polar regions, is covered by shortwave radio. With the introduction of GMDSS, the S.O.S signal is no longer used.
Morse Code is a sequence of short and long signals of lights or sounds used in communication. The International Morse Code identifies each latin alphabet letter with a series of short (dots) and long (dashes) signals.
A couple of weeks ago my S7 started to make a sound like morse code 'x' at a relatively low pitch, i.e. no high frequency tone. I cannot recall having installed any 3rd party app that could have triggered this. The beeping occurs at random intervals, varying between 15 minutes and several hours (yesterday at 15:37, 15.55, 16:20, 16:39, 17:40 etc.) and is particularly annoying at 4 a.m. or so. It also occurs when the phone is on "do not disturb", which I have activated for the night hours (11pm-5am). There is no message displayed with it either, and I am unable to relate it to any incoming message, alarm or notification. Also, it is not related to NFC or any other wireless signal (WiFi, BT, SmartThings) as I have disabled them one by one, but the beeping still went on. It occurs spontaneously, independent of location (bedroom, office, kitchen, out of the house...) and is independent of the phone being moved or sitting still.
Assuming that there is nobody out there who has the same phenomenon, does anyone of you, dear readers, know of any tool which could track the origin of such beeps and thus giving me a clue as to what could cause it? Caramba, it just beeped again :-((
Hi... You are not the only one. My S9 is doing the same. I have this phone for little over half a year but since recently it also makes this sound. Similar experiences, (....it just did it again...), no indication whatsoever where it could come from. And just like you, I thought it to be an "X" or a "Y" in Morse. It is driving me crazy as I cannot figure out where it comes from or how to shut it off. There is no standard notification sound just like it, neither one of the recently installed apps produces this sound. I've switched from iPhone to S9 but if this goes on for long I will move back..... :))
After my post above I booted my S7 into safe mode, in which there was no beep anymore. But this did not help me much further, it only indicated that the beep was probably caused by one of the apps that got disabled in safe mode. Switching back to regular mode I was anxious to hear that dreaded "da-di-di-da" beep again. However, keep fingers crossed, it has not appeared any more since then. My hope is that it will stay this way and that it was just a glitch in the bellows of Android which had caused it, weird as it was...
I have the exact same problem on my S9+, started today and beeps almost every 10-15 min without any notification. As you said only 2 solution come up online; NFC or Notification reminder. Both turned off, so it's not the case. I'll try safe mode now.
Thank you for your hints. Unfortunately there is/was nothing showing up on the Notification Panel, not even at the exact time when the beep occured, neither before, nor after. It just left no trace at all.
As I mentioned in my previous post, booting into safe mode and letting it run in safe mode for a few hours before switching back to normal mode seems to have helped. I have not had the beep anymore since then. Nevertheless thank you for your hints about the email notifications. All of them except for the one at the very bottom are "On", and the chime is set to "Letter". In case the dreaded da-di-di-da comes up again I shall certainly try switching them off.
My S8+ is sending me morsecode messages. Not sure if an alien is trying to contact a priveleged few or the recent software update is a frickin mess. Fortunately i put it on silent and no notification, else drives me nuts. Any one found a solution yet please?
My second Arduino project is about reading morse code. I have a board with a tactile switch which turns a LED on when pressed. An LDR connected to the same board reads the amount of light it receives. When LED is off pin 0 receives analogRead value < 100, when it's on (tactile switch pressed) it's well above it (300-400).
When the LDR is above the 100 treshold (switch is pressed and LED is on) it starts counting the number of milliseconds until the treshold gets below that (switch is released, LED is off). When the number milliseconds is lower than 700 ms, it's a short signal (dit), when it's between 700 and 1200 ms it's a long signal (dah), when it's above 1200 ms it's a space (signaling the start of the next letter).
This is all working fine, and I see that it gets correctly printed to the Serial, but when I want to compare the char array to convert morse (like "LLL") back to a alphabetic letter ("O" in this example) it doesn't work. The evaluation never returns true.
You can't compare two character arrays with '=='. That will compare the address of the first characters of the two strings and since the strainga are at different addresses they will never be 'equal'.
Yes, but that was the other way around. From a letter to morse. Now I want to do the opposite: from morse to letter. Is there a function to get the key for a value? Sorry for the n00b questions, I'm really new to C++.
Morse code can be thought of as Short, Long, and Space to mark End Of Character, a 3-state code.
You could use 2 binary bits to record that, one bit high to mark a tap and the next to mark short/low or long/high.
The way I encoded morse was to use a 0 for dot and 1 for dash. Of course that meant you didn't know how long a morse character was so the end of the character was marked with a 1. So an S for example ( three dots ) would show as 00001000, Then all you need to do to convert it into ASCII is to use a lookup table in an array. All morse characters can be encoded in a single byte.
I did automatic speed tracking as well. If I timed a signal and it was greater than the threshold then it was treated as a dash. Then the threshold was set at half what I timed the dash to be. If it was less than the threshold and so a dot I adjusted the threshold to be twice what I timed. In that way the receiver always locked onto any speed signal.
Developed in the 1830s and 1840s by Samuel Morse and other inventors, the telegraph revolutionized long-distance communication. It worked by transmitting electrical signals over a wire laid between stations. In addition to helping invent the telegraph, the Morse code assigned a set of dots and dashes to each letter of the English alphabet and allowed for the simple transmission of complex messages across telegraph lines. In 1844, Morse sent his first telegraph message, from Washington, D.C., to Baltimore, Maryland; by 1866, a telegraph line had been laid across the Atlantic Ocean from the United States to Europe. The telegraph had fallen out of widespread use by the 20th century, replaced by the telephone, fax machine and Internet.
Before the development of the electric telegraph in the 19th century revolutionized how information was transmitted across long distances, ancient civilizations such as those in China, Egypt and Greece used drumbeats, signal fires or smoke signals to exchange information between far-flung points.
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