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NXT Telegraph: Smart Move
Before IMing, before email - and even before the telephone - the telegraph let you send and receive messages in Morse Code. The NXT Telegraph lets you quickly and easily send messages from one brick to another. And, you can do the whole set-up from configuring the bricks to downloading and uploading the programs in under 10 minutes. The sender uses the NXT buttons to send a dot (.) with the left button or a dash (-) with the enter button. Both of you can hear the dots (A at .2 seconds) and dashes (F at .3 seconds) and the message is displayed on the receiver's display screen. You can send any length of message you want. When the line is filled, it starts a new line. When the screen is filled, it waits a short time and then clears the screen and starts over. To make it easier to decode the message, and mark the end of a letter, I've added a symbol that Samuel F.B. Morse didn't have - a space. The sender hits the right button, you both hear the next highest F at .1 seconds, and the reciever sees a blank space on the screen ( ).If you and your friend are real whizzes at Morse Code you might not need it, but I find it useful. The video shows a sending brick transmitting the message HI NXTLOG (as in the picture) to a dedicated receiving brick. I did this as I only have one sound sensor. If you have 2 bricks and 2 sound sensors you both can send and recieve. In that case, cable the sound sensor on your brick to port 2 of your friend's bricks and vice versa. If you are alone with only one brick and one sound sensor, just cable the sensor into your own port 2 and you can see what you are typing and practice your Morse code skills. You can make any kind of stand you want, or no stand at all. You have lots of flexibility in attaching the sound sensor as well. The important thing is that is right up against your brick and cabled into the other guy's port 2. The left bottom picture shows a sturdy way to attach the sound sensor and the right one shows a very simple but workable method. it's up to you. See below for the NXT-G program and MyBlocks you need, and a brief discription of why the program works the way it does. I hope you try this project. it's really fun to fool around with.

Posted by:

 snabeli

Created:

 14 April 2010

Rate:

 

Tags:(?):

 smartmove, informationtransport, sound, code, telegraph, video

Programs

(The pricture shows the message PROGRAMS in Morse Code.) Download the MyBlocks SENDmessage (left) and RECEIVEmessage (right) into your MyBlock folder making sure they have the exact same names. Download the program Telegraph into your Default folder as usual. All three files are fully commented, so if you would like to learn how the program works in detail, just download them and read it. But for a brief explanation..The sound sensor cannot detect pitch but using the timer you can see how long a sound remains at a certain level. Since the dot is at .2 seconds and the dash at .3, the program can tell the difference and display the right symbol. Read RECEIVEmessage to learn more.

Comments

10 most recent comments out of 29  [VIEW ALL]

  • snabeli

  • david msnxt, As I said above the sound sensor can NOT distinguish frequency, only voluume. This works because the reciever wait until it hears a sound greater than 95db, then enters a loop with a timer in it and ends when the sound drops to less than 93db. Then a series of range block deterermine how long the tone was and thus whether it was a dot, dash or space. Read the MyBlock for more.

  • Posted 1121 days and 12 hours ago


  • BigThor

  • Hey! I just discovered a cool thing you built into your program. If you type the letter V (..._) is sounds just like Beethoven's Fifth! Great!

  • Posted 1119 days and 1 hour ago


  • Dinoguy7719

  • Ha-ha! Very funny BigThor. Anyway, this is a cool project.

  • Posted 1118 days and 9 hours ago


  • a_friendly_balrog

  • snabeli: If I understand you correctly, you believe that the NXTs need a bluetooth connection from the computer. You only need Bluetooth on your computer if you want to download programs or use the remote control with it. The NXTs come with Bluetooth already on them. You do not need anything additional to use Bluetooth in your programs.

  • Posted 1118 days and 4 hours ago


  • snabeli

  • a friendly balroq, thank you very much! I am going to try that later today. And I just broke down and bought a dongle (at 50% off!) and it will arrive on the 11th. I think I might rewrite the Telegraph Station program using bluetooth instead of sound. Then you and your buddy can send silent Morse Code messages across enemy lines. Stay tuned! And I really appreciate your advice.

  • Posted 1110 days and 12 hours ago


  • I-am-a-ROBOT

  • its original, but not very funny.... Best luck the NXT time!

  • Posted 906 days and 12 hours ago


  • Alexanderkahn

  • thats nice! good thing I know morse codo that way i can use it!

  • Posted 892 days and 5 hours ago



  • milo-c

  • nice!!!!!!!!!!!!!!!!!

  • Posted 558 days and 11 hours ago


  • legowave440

  • They still use cw... in amateur radio! They communicate all around the world, without dependency on some weak system, (like cellular, internet, ect...)

  • Posted 505 days and 4 hours ago


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