Final Project for College [changed]

[SOTX]

hi guys,

morse code beacon and morse code receiver. [credits to the authors]

http://www.solorb.com/elect/beacon/index.html
**broken link removed**

Now ... being an electronic newbie that i am lol [mercy please]. From these circuits i would like to know what kind of output does the beacon give? sound? voltages? light? (from the diagram it kinda looks like sound but ...)

As for the receiver, does it also decode? (into words). It does say that we can connect a LCD display to it but ... will it give out words or just the . _ . _ _

sorry if some of these questions are stupid but ... noob ... Rolling Eyes
but i thank everyone who takes the time to post and help me out. appreciated a lot

ps: i would also like to know what's the role of the chips in these circuits please ? THANK YOU

 

[akg]

Re: Final Project for College

hi guys,

i want to build one of two projects which is a textphone or a caller display.

textphone: read out whatever is typed in (could be each letter or a whole word). input will probably be from a PC using RS232 interface.

caller display: when incoming call is detected, display on the PC monitor the number and name of caller (and log the call). will also use RS232 interface.

i would appreciated it anyone can tell me what kind of chips can be use... any info will be greatly appreciated. THX

textphone: read out whatever is typed in (could be each letter or a whole word). input will probably be from a PC using RS232 interface.

i didn't understand what u mean by this

caller display: when incoming call is detected, display on the PC monitor the number and name of caller (and log the call). will also use RS232 interface.

ok..the caller id signal is send thru the phone line just after the first ring as dtmf tones. so u can have a dtmf decoder like 8870 to detect these tone.
u may also need a micro to decode and send as rs232 signals to pc ., or with extra effort thru lpt w/o using the micro.
in the pc u need a database for the number search and can log it with time
see the datasheet for 8870 , the decoder ckt is explained there.

 

[Edigate]

Hello,
I think I have a similar project.
I need to write a program (+ create a database) that would send data from a cellphone to a computer and vice versa using either the serial or parallel port.
I think we can work together, though I'm starting from the scratch.

 

[jbeng]

Re: Final Project for College

i didn't understand what u mean by this

Essentially, what SOTX is describing here is a device we often refer to here in the states as a TTY. It's a text device used by the deaf to communicate via telephone lines.

ok..the caller id signal is send thru the phone line just after the first ring as dtmf tones. so u can have a dtmf decoder like 8870 to detect these tone.

This is not how it's done in the states. Here is a link to a datasheet for a chip from Motorola which interfaces to the phone line to extract the serial digital data which is sent at 1200 baud (Bell 202 protocol) between the first and second rings. See page 4 for the datastream specifications. Page 5 has a sample circuit and timing diagrams. Page 6 has diagrams of the message formats which are used. It's a pretty crappy scan of the datasheet, but the info's all there.

https://www.electro-tech-online.com/custompdfs/2005/12/MC145447P.pdf

As I said, these standards are for the US and may not be applicable worldwide. But then SOTX, like so many other ETO members, has failed to provide us with his (her?) country of origin. Personally, I don't think you should be able to make posts without entering this information. But then, that's just me ... :x
JB

 

[SOTX]

yeah i just realize that problem ... i dont think i can just tap in and detect these signals myself can i ? this is a paid service so ... if people can do this ... then they'd lose a whole lot of money... i guess ?

um ... another interesting subject is a morse code beacon and morse code receiver. [credits to the authors]

http://www.solorb.com/elect/beacon/index.html
**broken link removed**

Now ... being an electronic newbie that i am lol [mercy please]. From these circuits i would like to know what kind of output does the beacon give? sound? voltages? light? (from the diagram it kinda looks like sound but ...)

As for the receiver, does it also decode? (into words). It does say that we can connect a LCD display to it but ... will it give out words or just the . _ . _ _

sorry if some of these questions are stupid but ... noob ... :roll:
but i thank everyone who takes the time to post and help me out. appreciated a lot

 

[akg]

the morese code becon as explained in the ckt seq send the morese code signal that is stored in the eprom .

the relay will make and break according to the code, played from the eprom.
u need to store the morecode patterns in the eprom in the begining.
then u need to convert the make and break of the relay to ur need.

as far as the decoder is concerned , it think it will convert the code to characters to display in the lcd.but u need the program for the 16f84

 

[jbeng]

... i dont think i can just tap in and detect these signals myself can i ? this is a paid service so ...

Yes, you have to pay the phone company to enable the data to be sent to your phone when it rings.

Also, I see you've entered your location. Hope I didn't offend about that, but we get a lot of folks here asking questions which can be answered differently based on the region they live. If that info isn't filled in, it makes it tough to give an accurate answer.
JB

 

[SOTX]

Can you guys tell me what are the role of each IC in these circuits please ? i know there's not a lot but i just want to be clear on their functions. THANK YOU

 

[akg]

Can you guys tell me what are the role of each IC in these circuits please ? i know there's not a lot but i just want to be clear on their functions. THANK YOU

i recommend u to download and see the datasheets of the ics from
www.alldatasheet.com. so that u can understand it in deatil.

the IC U1(c&d) forms a free running oscillator which is controlled by U1(a&b)
this o/p is connecte to 4040 which is a 12 stage binary counter, this decoded signal is given to the eprom as the address bits, this selects the data at corresponding address in the eprom thru the data o/p pins (d0-d7), only one is used , so 1 bit on/off , this switches the transistor and the relay..

in case of the decoder the parts are labeled ,the f84 is a microcontroller , so u need the program also to check the working of the ckt

 

[SOTX]

thanks a lot for replying ...

well i do know and have used most of these chips. i just would like to confirm their FUNCTION in the system...

 

[akg]

thanks a lot for replying ...

well i do know and have used most of these chips. i just would like to confirm their FUNCTION in the system...

if u have used the ics and know what they are , then i'm sorry that i don't understand ur above statement

 

[demokesola]

Different chips Differnt functions: you've got registers, counter, display drivers, comparators...etc.

Check your data sheets

 

[SOTX]

well basically i know what they do but in this example ... what are they trying to get using these chips. (ex: using certain to have the right timing...)