Com ports over bluetooth

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Guest

Hi there,

We're trying to communicate with a PPC (O2 Orbit, windows mobile 5) using
COM Ports over bluetooth which have done sucessfully, sending data in both
directions. (VS2005 .netCF v2)

However, we're now trying to mointor the status of the RTS / CTS pin and
although we can set it both ends, on the PPC end the status is not updated -
does anyone have any suggestions?

We're using Bluetooth connecter from LM Technologies.

Thanks
 
There's no pins to monitor. It's not a real serial port; it's just creating
an abstract "serial port" sort of connection over the Bluetooth radio that
you can treat as though it's a local port.

Paul T.
 
Hi,

Like Paul states, most Bluerooth serial adapters do not support hardware
lines. It would be possible to design this function into the BT hardware
and driver -- but I know of no one who has done so.

I do this on my RemoteComm/LocalCom (Downloads on my homepage), but these
run over a standard TCP/IP network (including WiFi), and require a PC (PPC
is possible, though I haven't done that) to provide tthe physical serial
port. I created a packet protocol that includes all of the hardware signals
from the host serial port (plus a number of exception messages) AND some
other in-band messages for special signalling. Many of these things are not
done in most other similar software/hardware combos.

Dick



--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.
 
Hi,

Thanks for the reply.

At both ends we can get/set the RTS/CTS status - are you saying that because
it's via a bluetooth "logical" port the pins statuses aren't carried?

Matt
 
It would shock me completely if they were. There's just no reason for them
to be. It's the data that's important.

Paul T.
 
They are usually used as hardwarw flow control.
You have no hardware connected ....
You probably need it in order to signal something.
Maybe you can use a special packet to do that.





"Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam DOT
com> wrote in message news:%[email protected]...
 
Hardware flow control for what? The other end is a BT receiver. The BT
statck and protocol handle making sure all data is transmitted error free.
Serial "flow control" has no meaning in a BT environment.


--

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Managed Code in an Embedded World
www.OpenNETCF.com


Empi said:
They are usually used as hardwarw flow control.
You have no hardware connected ....
You probably need it in order to signal something.
Maybe you can use a special packet to do that.





"Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam DOT
com> wrote in message news:%[email protected]...
It would shock me completely if they were. There's just no reason for
them to be. It's the data that's important.

Paul T.
Click to expand...
Click to expand...
 
Thanks for all your replies - they've been very helpful in understanding why
it's not working :)

The reason we're trying to do this is to monitor the state of a serial pin
on a very old device using a PDA - our plan was to wire the old device to the
CTS pin on a bluetooth transmitter and monitor the signal across bluetooth
using the virtual serial port connection.

Obviously this now won't work but does anyone have any suggestions as to how
we might do it? Is there a piece of hardware we could but to take an on/off
serial siganl and send it via bluetooth?

Thanks!

Hardware flow control for what? The other end is a BT receiver. The BT
statck and protocol handle making sure all data is transmitted error free.
Serial "flow control" has no meaning in a BT environment.


--

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Managed Code in an Embedded World
www.OpenNETCF.com


Empi said:
They are usually used as hardwarw flow control.
You have no hardware connected ....
You probably need it in order to signal something.
Maybe you can use a special packet to do that.





"Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam DOT
com> wrote in message news:%[email protected]...
It would shock me completely if they were. There's just no reason for
them to be. It's the data that's important.

Paul T.

Hi,

Thanks for the reply.

At both ends we can get/set the RTS/CTS status - are you saying that
because
it's via a bluetooth "logical" port the pins statuses aren't carried?

Matt

:

There's no pins to monitor. It's not a real serial port; it's just
creating
an abstract "serial port" sort of connection over the Bluetooth radio
that
you can treat as though it's a local port.

Paul T.

Hi there,

We're trying to communicate with a PPC (O2 Orbit, windows mobile 5)
using
COM Ports over bluetooth which have done sucessfully, sending data in
both
directions. (VS2005 .netCF v2)

However, we're now trying to mointor the status of the RTS / CTS pin
and
although we can set it both ends, on the PPC end the status is not
updated -
does anyone have any suggestions?

We're using Bluetooth connecter from LM Technologies.

Thanks
Click to expand...
Click to expand...
Click to expand...
 
You could build such a piece of hardware, although I can't imagine that the
cost of that would be worthwhile unless this old equipment is a $10,000+
sort of device. We have various Ethernet-based devices for remotely
monitoring signals and many other companies have similar devices. I'm not
aware of any Bluetooth ones, but they might be out there. www.edasce.com

Paul T.

CabMaster said:
Thanks for all your replies - they've been very helpful in understanding
why
it's not working :)

The reason we're trying to do this is to monitor the state of a serial pin
on a very old device using a PDA - our plan was to wire the old device to
the
CTS pin on a bluetooth transmitter and monitor the signal across bluetooth
using the virtual serial port connection.

Obviously this now won't work but does anyone have any suggestions as to
how
we might do it? Is there a piece of hardware we could but to take an
on/off
serial siganl and send it via bluetooth?

Thanks!

Hardware flow control for what? The other end is a BT receiver. The BT
statck and protocol handle making sure all data is transmitted error
free.
Serial "flow control" has no meaning in a BT environment.


--

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Managed Code in an Embedded World
www.OpenNETCF.com


Empi said:
They are usually used as hardwarw flow control.
You have no hardware connected ....
You probably need it in order to signal something.
Maybe you can use a special packet to do that.





"Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam
DOT
com> wrote in message It would shock me completely if they were. There's just no reason for
them to be. It's the data that's important.

Paul T.

Hi,

Thanks for the reply.

At both ends we can get/set the RTS/CTS status - are you saying that
because
it's via a bluetooth "logical" port the pins statuses aren't carried?

Matt

:

There's no pins to monitor. It's not a real serial port; it's just
creating
an abstract "serial port" sort of connection over the Bluetooth
radio
that
you can treat as though it's a local port.

Paul T.

Hi there,

We're trying to communicate with a PPC (O2 Orbit, windows mobile
5)
using
COM Ports over bluetooth which have done sucessfully, sending data
in
both
directions. (VS2005 .netCF v2)

However, we're now trying to mointor the status of the RTS / CTS
pin
and
although we can set it both ends, on the PPC end the status is not
updated -
does anyone have any suggestions?

We're using Bluetooth connecter from LM Technologies.

Thanks
Click to expand...
Click to expand...
Click to expand...
 
Hi,

It would be straight-forward to write a small program that executes on a
microcontroller board that detects one (or more) switch states. The
microcontroller could output a serial message that could be send via BT
(using your existing BT adapter and the microcontroller's serial port) with
each switch state change (e.g., "SWITCH1=1" -- just for example).

I don't know of any "pre-built" designs for this specific purpose, but...
There are lots of inexpensive off-the-shelf evaluation boards that could be
used with a few hours of work to make this happen.

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.
 
Hi Paul,

The hardware required might be as little as $20 (to add to OP's existing BT
adapter). For example, the simplest PIC Basic board from Parallax costs $15
plus shipping. The BASIC language interpreter for it is a free download.
It has a serial interface, and power connections, along with a spot on the
board where one could connect the switches to be monitored. Less than (my
guess) two hours later, it should be working.

OK, so I suspect that you would have to use a null modem adapter with it.
My BT serial adapter came with a null modem, so...

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.
 
As a prototype that would work, but I think Paul's point is that if this is
going to be some production thing then there's a lot to consider for
business justification and rethinking it, or searching for some
off-the-shelf solution might be worthwhile. It's going to need plastics.
It's going to need soldering. It probably will need a custom PCB. It might
need some form of UL/CE/FTC certification.

It might be a lot easier to just use something like this:
http://www.wcscnet.com/HdwHPS120.htm


--

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Managed Code in an Embedded World
www.OpenNETCF.com
 
Power supply, isolation from the equipment, etc., too. If the port is a 5V
TTL port, the standard GPIO on most processors will handle it, but, if it's
really RS-232, you need something with a wider range and different levels.
If you build it yourself, you don't have to pay margin, but, if you buy it
you do. It would be an interesting project!

Paul T.
 
Hi Chris,

From OP's comments, I was "thought" this was one-of. Of course, thought
isn't certain. Even so, the same code would work in production, and the
same general hardware could be used -- the cost would be about the same,
even with an enclosure. Power for the micro would be the only question, I
think.

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.
 
Hi Paul,

The board that I mentioned does have a RS232 port. Since it is powered from
a 9V battery, the levels aren't EXACTLY "standard." But, I've never seen a
problem. Since OP is using a BT serial adapter, he already has to solve the
issue of powering the BT adapter, since none that I have seen are powered
from the RS232 port.

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.
 
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