The way that you have the sender and receiver hooked together means you don't have to worry too much about noise on the incoming signal. I wouldn't use a separate function to send each letter, but it's your project and you have to do something yourself.ĭecoding is whole different problem, but if you get the transmission timing right and set up the decoder properly you can increase or decrease the transmission speed and still have the decoder figure it out.
WB7FHC CW DECODER CODE
So, your code should be more like this: #define DIT_LENGTH 100įYI the way to convert a morse code speed in words per minute (WPM) into the length of a dit in milliseconds is simply: Between letters there's another space that is 3 dits long and the word space is 7 dits long. From that, a dah is 3*dit and the silence between them is also one dit long. The unit of time for morse code is based on the length of the "dit". The timing of your morse code transmission isn't very good. T->pCallSign = ++pC //start of next segment of callsign *pM = ‘\0’ //terminating null for Morse Buffer *pM++ = delay //overwrite with delay at end of callsign PC++ //advance to next letter to be translated *–pM = ‘\3’ //overwrite with an inter-letter pause *pM++ = ‘\1’ //store duration of inter-element pause *pM++ = MC //store duration of this Morse element For each Morse element (dot or dash) of the character Get pointer to next character’s Morse sequence string/ While the next call sign character is not a semicolon T->Key = FALSE //set morse key to the off state If((int delay = (int)*pC++) Key = TRUE //set morse key to the on stateĭelay = -delay //reverse its sign (make it positive)} T->Repeat = (int)*pC++ //Nº of times it is to be repeated T->Pitch = (int)*pC++ //audio frequency of keying tone PC = t->CallSign //reset ptr to start of callsign data If(*pC = ‘\0’) //if we’ve reached end of callsign data *pM = t->pMorse //ptr to start of stn’s Morse string *pC = t->pCallSign, //ptr to start of next callsign segment *pMC, //ptr to Morse element in MorseCode The code for each letter is expressed as timer Array letters of the Morse Code alphabet where t = ptr to Tx Data structure of stn currently being keyed The following function gets the next callsign segment from CallSign and sets it up as a string of Morse Code timer durations in Morse :
WB7FHC CW DECODER SIMULATOR
And for the final part, the CPU interfaces to the LCD line display, sending ASCII characters to it and monitoring LCD status.Ok but I needed Morse Code transmitter for my flight simulator it takes input from a database and it chucks it out… easy Each of the symbols that are received, an equivalent "code word" is assembled and is convert to its ASCII equivalent character for display. This output drives both an input to the PIC16F84 microcontroller and an LED that is used as a receiver tuning aid.Īnother part is the PIC16F84 microcontroller, its function is to measure the duration of the one-zero input string from the tone decoder, and translate the pattern into DOTs, DASHs, symbol spaces, character spaces, or word spaces. The next part of the project is the PLL (phase lock loop) tone detector/decoder NE567 its output is a one-zero pattern replicating the dots-and-dashes sequence of the received signal. Its band edges are determined by the size of the coupling capacitors, and the feedback capacitor between the transistor's base and collector terminals. The project's first part is composed of an electret microphone followed by a common emitter follower amplifier this transistor amplifier also acts as a first level bandpass filter. Compared to voice, Morse code is less sensitive to poor signal conditions, yet still comprehensible to humans without a decoding device, therefore, a useful alternative to synthesized speech for sending automated data to skilled listeners (radio operator) on a voice channel. Each character (letter or numeral) is coded/represented by a unique sequence of dots and dashes. Morse code is used in telecommunication it is a method of transmitting and receiving coded information.
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