Post by thread:[EE] What could you put in a serial cable?

If you were going to put a little microcontroller (like a PIC) and a small LCD display in a serial cable, what sort of information would you want the LCD to display? We are talking like 8 characters here, not a 4x20. It might even be an LED. But as long as the PIC has to be there anyway, why not have it do something interesting? Here are my initial ideas: - Auto detected baud rate. It might not always be totally accurate, but it would be nice to have a sanity check on the data being sent... "Did this thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are just seeing garbage" - Parity. If it appears that there is a valid Parity in the stream after some number of bytes, put an "E" or "O" on the display or light an LED next to a printed "P" green for Even, red for Odd. - Stop bits? - Last character through the cable at the auto detected rate? - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is released. - Blank display 2 seconds after the last signal goes through. So if you were connected to a device that was sending a string at 9600E81 and your buffer filled up you might see the following in sequence: "9600", "9600E81", "XOFF", "XON", "9600", " " What would you want to see, or think it would be possible to add? --- James.

Well, there are 8 lines: DTR DSR DCD CTS RTS RI TX RX You might consider reserving one character for each line, and lighting it (for signals) for a second when active. For the TX and RX, just display the last character in their spot. Or, get rid of the lesser used lines, and reserve 3 spaces for detected speed: 1k2, 2k4, 4k8, 9k6, 19k, m11, m25, etc. Or save 3 for speed, 2 for tx and rx data, and the last 3 can tell which three of the other lines are active (and if too many then scroll through that little 3 character space) Or list everything and use scrolling. You've got 8 custom characters, so you could have TX normal, and invert RX and scroll all the data across the display. If you've got enough space and a writable PIC, put a bootloader in there. -Adam On 3/16/07, James Newtons Massmind <spam_OUTjamesnewtonTakeThisOuTmassmind.org> wrote: {Quote hidden}> If you were going to put a little microcontroller (like a PIC) and a small > LCD display in a serial cable, what sort of information would you want the > LCD to display? > > We are talking like 8 characters here, not a 4x20. It might even be an LED. > > But as long as the PIC has to be there anyway, why not have it do something > interesting? > > Here are my initial ideas: > - Auto detected baud rate. It might not always be totally accurate, but it > would be nice to have a sanity check on the data being sent... "Did this > thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are > just seeing garbage" > > - Parity. If it appears that there is a valid Parity in the stream after > some number of bytes, put an "E" or "O" on the display or light an LED next > to a printed "P" green for Even, red for Odd. > > - Stop bits? > > - Last character through the cable at the auto detected rate? > > - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is > released. > > - Blank display 2 seconds after the last signal goes through. > > So if you were connected to a device that was sending a string at 9600E81 > and your buffer filled up you might see the following in sequence: > > "9600", "9600E81", "XOFF", "XON", "9600", " " > > What would you want to see, or think it would be possible to add? > > --- > James. > > > -

How about the ability to send out a message at a given baud rate? An "Is this thing receiving?" message could be helpful in knowing if you had the right connections, serial port, etc in your terminal software. Jon At 12:31 PM 3/16/2007 -0700, you wrote: {Quote hidden}>If you were going to put a little microcontroller (like a PIC) and a small >LCD display in a serial cable, what sort of information would you want the >LCD to display? > >We are talking like 8 characters here, not a 4x20. It might even be an LED. > >But as long as the PIC has to be there anyway, why not have it do something >interesting? > >Here are my initial ideas: >- Auto detected baud rate. It might not always be totally accurate, but it >would be nice to have a sanity check on the data being sent... "Did this >thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are >just seeing garbage" > >- Parity. If it appears that there is a valid Parity in the stream after >some number of bytes, put an "E" or "O" on the display or light an LED next >to a printed "P" green for Even, red for Odd. > >- Stop bits? > >- Last character through the cable at the auto detected rate? > >- "+DTR", "-CTS" etc... For 1 second after the signal asserts or is >released. > >- Blank display 2 seconds after the last signal goes through. > >So if you were connected to a device that was sending a string at 9600E81 >and your buffer filled up you might see the following in sequence: > >"9600", "9600E81", "XOFF", "XON", "9600", " " > >What would you want to see, or think it would be possible to add? > >--- >James. > > >

Jon Chandler .....chandlerKILLspam@spam@seanet.com wrote: >How about the ability to send out a message at a given baud rate? >An "Is this thing receiving?" message could be helpful in knowing >if you had the right connections, serial port, etc in your terminal >software. >Jon I have a RS232 tester that in one of its modes sends 110 600 1200 2400 4800 etc each in its baudrate so on an attached device you see garbled stuff with the currently selected baudrate readable. handy if you have a printer or terminal without a discription of the dipswitches. I aggree with one of the other posters though, RS232 is rapidly loosing ground. It's hard to find a laptop that still has one, printers dont support RS232 anymore etc. Peter van Hoof

On Mar 16, 2007, at 12:31 PM, James Newtons Massmind wrote: > - Auto detected baud rate. > - Parity. > - Stop bits? Sure. The whole "mode" string if you can. > > - Last character through the cable at the auto detected rate? Buffer as much data as possible, and have a way to display it at human-readable rates... > - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is > released. Ok. > - Blank display 2 seconds after the last signal goes through. > Rather than blank, it should revert to some sort of pin-state display. It would be nice if it sanity-checked your connections, too, and produced some sort of warning if one of the data pins had no driver attached (for example.) BillW

> I aggree with one of the other posters though, RS232 is > rapidly loosing ground. > It's hard to find a laptop that still has one, printers dont > support RS232 anymore etc. In the PC world, yes, there is little need for RS232. In the embedded world, there are TONS of little devices that use async serial to communicate. For example, look at the number of things available for connection to the BASIC STAMP. http://www.parallax.com/html_pages/products/accessories/accessories.asp And if you want to talk to, or listen in on, one of those devices with your PC during development, you may find you need a little gizmo to convert TTL to RS232 so your USB/RS232 adapter will work. <PLUG> Now, there are a billion designs for such a thing, but rather than take the time, you can just keep one of these on hand: www.piclist.com/techref/io/serial/rcl1.htm </PLUG> And I was thinking about what could possible make it more useful to people. Just idle thought.

On 3/16/07, James Newtons Massmind <jamesnewtonKILLspammassmind.org> wrote: > If you were going to put a little microcontroller (like a PIC) and a small > LCD display in a serial cable, what sort of information would you want the > LCD to display? > > We are talking like 8 characters here, not a 4x20. It might even be an LED. The following sentence rolling : "buy a scope" :) > > But as long as the PIC has to be there anyway, why not have it do something > interesting? > > Here are my initial ideas: > - Auto detected baud rate. It might not always be totally accurate Than it has nonsense. Imagine a voltmeter which sometime is not displaying the real voltage... :( , but it > would be nice to have a sanity check on the data being sent... "Did this > thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are > just seeing garbage" > > - Parity. If it appears that there is a valid Parity in the stream after > some number of bytes, put an "E" or "O" on the display or light an LED next > to a printed "P" green for Even, red for Odd. > > - Stop bits? The stop bits are not necessary. A communication set in one end for 2 stop bits will usually work as well with 1 or 1.5 stop bits in the other end... > > - Last character through the cable at the auto detected rate? > > - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is > released. > > - Blank display 2 seconds after the last signal goes through. Maybe else than a blank display, like "***" > > So if you were connected to a device that was sending a string at 9600E81 > and your buffer filled up you might see the following in sequence: > > "9600", "9600E81", "XOFF", "XON", "9600", " " > > What would you want to see, or think it would be possible to add? Unusefull things for commercial purposes ? like: this device is displaying everything about an RS232 communication... :) geetings, Vasile

You've probably visited these sites in the past. I think would gave you some clues: http://members.cox.net/berniekm/super.html http://www.qsl.net/la9sja/electronics/ea/ I hope you realise I care (just a little) about your problems even I'm joking. Vasile On 3/16/07, Vasile Surducan <.....piclist9KILLspam.....gmail.com> wrote: {Quote hidden}> On 3/16/07, James Newtons Massmind <EraseMEjamesnewtonspam_OUTTakeThisOuTmassmind.org> wrote: > > If you were going to put a little microcontroller (like a PIC) and a small > > LCD display in a serial cable, what sort of information would you want the > > LCD to display? > > > > We are talking like 8 characters here, not a 4x20. It might even be an LED. > > The following sentence rolling : "buy a scope" > :) > > > > > But as long as the PIC has to be there anyway, why not have it do something > > interesting? > > > > Here are my initial ideas: > > - Auto detected baud rate. It might not always be totally accurate > > Than it has nonsense. Imagine a voltmeter which sometime is not > displaying the real voltage... > :( > > , but it > > would be nice to have a sanity check on the data being sent... "Did this > > thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are > > just seeing garbage" > > > > - Parity. If it appears that there is a valid Parity in the stream after > > some number of bytes, put an "E" or "O" on the display or light an LED next > > to a printed "P" green for Even, red for Odd. > > > > - Stop bits? > > The stop bits are not necessary. A communication set in one end for 2 > stop bits will usually work as well with 1 or 1.5 stop bits in the > other end... > > > > > - Last character through the cable at the auto detected rate? > > > > - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is > > released. > > > > > > - Blank display 2 seconds after the last signal goes through. > > Maybe else than a blank display, like "***" > > > > > So if you were connected to a device that was sending a string at 9600E81 > > and your buffer filled up you might see the following in sequence: > > > > "9600", "9600E81", "XOFF", "XON", "9600", " " > > > > What would you want to see, or think it would be possible to add? > > Unusefull things for commercial purposes ? > like: this device is displaying everything about an RS232 communication... > :) > > geetings, > Vasile >

James Newtons Massmind wrote: > <PLUG> > Now, there are a billion designs for such a thing, but rather than > take the time, you can just keep one of these on hand: > www.piclist.com/techref/io/serial/rcl1.htm > </PLUG> Or mine at http://www.embedinc.com/products/ser for less money, especially in 5 packs. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.

On 3/17/07, Vasile Surducan <piclist9spam_OUTgmail.com> wrote: > On 3/16/07, James Newtons Massmind <@spam@jamesnewtonKILLspammassmind.org> wrote: > > - Stop bits? > > The stop bits are not necessary. A communication set in one end for 2 > stop bits will usually work as well with 1 or 1.5 stop bits in the > other end... Not true, unless there is a space between each byte. If the 1 or 1.5 stop bit end is sending data full bore with no time between bytes, then the 2 stop bit end _should_ report a framing error. In many cases there is space between the bytes, so it's not an issue, but I certainly wouldn't want to base the stability of my system on this shortcut. But the reality is that you can only "guess" what the stop bit length is with a microcontroller in the middle. If two bytes are never sent in sequence with no space between them, you'll never know the stop bit length. -Adam - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ Interested in electronics? Check out the projects at http://ubasics.com Building your own house? Check out http://ubasics.com/home/

James, Did you ever come to a conclusion as to what to include? I'd be interested to see the final product! Cheers, Howard Winter St.Albans, England On Fri, 16 Mar 2007 12:31:20 -0700, James Newtons Massmind wrote: {Quote hidden}> If you were going to put a little microcontroller (like a PIC) and a small > LCD display in a serial cable, what sort of information would you want the > LCD to display? > > We are talking like 8 characters here, not a 4x20. It might even be an LED. > > But as long as the PIC has to be there anyway, why not have it do something > interesting? > > Here are my initial ideas: > - Auto detected baud rate. It might not always be totally accurate, but it > would be nice to have a sanity check on the data being sent... "Did this > thing not get set to 9600?" "Oh, it's sending at 19.2... No wonder we are > just seeing garbage" > > - Parity. If it appears that there is a valid Parity in the stream after > some number of bytes, put an "E" or "O" on the display or light an LED next > to a printed "P" green for Even, red for Odd. > > - Stop bits? > > - Last character through the cable at the auto detected rate? > > - "+DTR", "-CTS" etc... For 1 second after the signal asserts or is > released. > > - Blank display 2 seconds after the last signal goes through. > > So if you were connected to a device that was sending a string at 9600E81 > and your buffer filled up you might see the following in sequence: > > "9600", "9600E81", "XOFF", "XON", "9600", " " > > What would you want to see, or think it would be possible to add? > > --- > James. > > > --