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by **Stef Mientki** » Sat Dec 03, 2005 12:34 am

hello,

I thinking of realizing a wireless link, from a portable PIC system to a PC.
The needed datarate is about 100 kbit.
No (or maybe very slow) data from PC to PIC.

Another requirement is to use as much standard components as possible.

So there seems 2 ways to go: wifi or bluetooth.

Now my guess is that bluetooth devices are easier to interface with a pic,
and more general available (in small quantities) then wifi.

Anyone has experience with these interfaces ?
Any other comment ?

thanks,
Stef Mientki

by **R Adsett** » Sat Dec 03, 2005 9:15 am

In article <El0kf.9229$Cj5.3949@newsfe6-win.ntli.net>,
tech@picmodules.com says...

My suggestion would be to get hold of one of those RS485 to RS232
converters. Hook it up to a PC serial port and connect the RS485 end to the
bus. You will not need to transmit onto the bus and so this should be quite
easy. Next, scope the waveform on the bus and determine the baud rate and
bit depth, stop bits etc. Then set these parameters in hyperminal and see
what data you capture. Unfortunately because hyperterminal is not a binary
to ASCII converter you will only see ASCII valid charaters and its possbile
that some data will be lost. Once you have this working then you need to
find/beg/borrow/write etc. an application that allows you to capture binary
data (0-255) and be able to display the digits 0-255.

Or just use a reasonable terminal emulator. For Windows based PCs
Realterm come to mind but there are others. FOr that matter it was
possible to do this with PC-Kermit if I remember correctly.
Hyperterminal is worth rather less than you paid for it.

Robert

by **Daniele** » Wed Dec 14, 2005 3:53 pm

Well, after some day of work i have this trouble:
- I don't know what is the speed of the device
- I don't know how many bit it ues
- I don't know if parity bit is present

Then when I connect the PC with the two device, the display of second
device (the keyboard, with lcd display) send a connection error (open
the connection via Hyperterminal).
What my problem? How i can decide what is the configuration parameters
for Hyperterminal (speed, data bit number, parity, stop bit number,
ecc...)? It's linked with integrate type? I can read the IC's part
number than I can search for spech?

Thanks in advanced
Daniele

by **Meindert Sprang** » Wed Dec 14, 2005 4:01 pm

"Daniele" <daniele.gadaleta@gmail.com> wrote in message
news:1134553987.032115.131100@o13g2000cwo.googlegroups.com...

Well, after some day of work i have this trouble:
- I don't know what is the speed of the device

With an oscilloscope, you can tell the speed within seconds.

- I don't know how many bit it ues

If single bytes are sent with delays between, see above.

- I don't know if parity bit is present

See above.

Then when I connect the PC with the two device, the display of second
device (the keyboard, with lcd display) send a connection error (open
the connection via Hyperterminal).

Hyperterminal is crap. When you open a com port with data present, hyperterm
says it cannot open the port in 95% of the cases. This is a hyperterminal
error. Use for instance TeraTerm (free), which works like a charm. With TT
you can also change all com settings (baud, bits etc) on the fly without
having to close the connection first, like hyperterm wants.

What my problem? How i can decide what is the configuration parameters
for Hyperterminal (speed, data bit number, parity, stop bit number,
ecc...)? It's linked with integrate type? I can read the IC's part
number than I can search for spech?

Drop hyperterm and use decent software.

Meindert

by **Daniele** » Wed Dec 14, 2005 4:05 pm

What software? can you give me some one?

by **Meindert Sprang** » Wed Dec 14, 2005 4:50 pm

"Daniele" <daniele.gadaleta@gmail.com> wrote in message
news:1134554758.157523.86980@g49g2000cwa.googlegroups.com...

What software? can you give me some one?

Sigh, I qoute from my reply:

"Use for instance TeraTerm (free), which works like a charm"

So, go to www.google.com, enter TeraTerm and download it from the first
link......

Meindert

by **Daniele** » Wed Dec 14, 2005 5:14 pm

Yes, excuse me. I read all your reply.
But now i have another doubt. Is my configuration true?

DEVICE 1 DEVICE 2
RS 485 RS 485
------------ -----------
| + - A B | | + - A B |
------------ -----------
| | | | | | | |
| | | | | | | ^
| | | +-----------------------------|
| | | | | | ^
| | +-|---------------------------|
| | | | | ^
| +-|-|-------------------------|
| | | | ^
+-|-|-|-----------------------|
| | | |
| | | |
------------
| + - A B |
------------
RS 232-485 Converter

by **Meindert Sprang** » Wed Dec 14, 2005 5:15 pm

"Daniele" <daniele.gadaleta@gmail.com> wrote in message
news:1134558858.407317.104090@o13g2000cwo.googlegroups.com...

Yes, excuse me. I read all your reply.
But now i have another doubt. Is my configuration true?

Yes. Just make sure you apply the right level to the RTS line on your
converter since this is mostly used to switch between transmitting and
receiving. And you want to be receiving only.

Meindert

by **Grant Edwards** » Wed Dec 14, 2005 5:15 pm

On 2005-12-14, Daniele <daniele.gadaleta@gmail.com> wrote:

Well, after some day of work i have this trouble:
- I don't know what is the speed of the device
- I don't know how many bit it ues
- I don't know if parity bit is present

A few minutes with a 'scope will answer most/all of those
questions.

Then when I connect the PC with the two device, the display of second
device (the keyboard, with lcd display) send a connection error (open
the connection via Hyperterminal).
What my problem?

You're using the wrong tools. First step is an oscilloscope.

Your second problem, you're using Hyperterminal.

How i can decide what is the configuration parameters for
Hyperterminal (speed, data bit number, parity, stop bit
number, ecc...)?

Oscilloscope. Prefereably a digital storage scope one with two
channels that can be set up differentially.

It's linked with integrate type? I can read the IC's part
number than I can search for spech?

--
Grant Edwards grante Yow! .. Now KEN and BARBIE
at are PERMANENTLY ADDICTED to
visi.com MIND-ALTERING DRUGS...

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Monitoring RS485

wireless ... bluetooth ?

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