pda->usb->RS232

  • Thread starter Thread starter Rainer Queck
  • Start date Start date
R

Rainer Queck

Hi NG,

I have a little project to do.
I need to "talk" to a microcontroller device (RS232) from a pda (wich only
has USB) .
This program is to be developed with C# using VS2005 professional (as soon
as I get it delivered).

Since I have no idea on how to approach this project (yet), I very much
appreciate any hints, links and help on how to get started.

Thanks in advance
Rainer Queck
 
VS.NET 2003 and CF 1.0 did not give support to serial communication and
was neccessary to use the awesome Smart Device framework from
http://www.opennetcf.org, which contains namespaces for serial
communication.
Now, VS.NET 2005 and its corresponding CF 2.0 will allow you to talk to
devices via serial port very easily. They now bring a simple class to
make easier your life. Take a look at:

http://msdn2.microsoft.com/library/30swa673(en-us,vs.80).aspx

There are many USB-Serial adapters. Surf the internet.

Hope it helps. Regards.
 
thanks for the info!
Will start reading soon :-)
And... yes any hints, linke will help me at the stage I am at the moment;-)

Regards
Rainer
 
Hi Chris,

I never digged into USB theory, so am not sure, about "USB_HOST_capability".
My pda is hooked up to my pc by a usb connecton.
So, you don't think that it is possible do comunicate with a pda via
usb/RS232 to a microcontroller?

Regards
Rainer
 
Most of the PDAs have a separate cable that is used (generally) with
ActiveSync over serial. Those cables can be used for general serial port
stuff. FWIR, the RS232 connection is usually nulled, so it will work when
connecting to a computer, but you'd need to de-null it to work with other
devices (GPS, modems, etc)
 
What model PDA is it? Usually PDAs have a physical RS232 option via an
RS232 cable.
My pda is hooked up to my pc by a usb connecton.
Click to expand...

so in this case the PC is the USB host, PDAs don't usually have the ability
to be the USB host only to connect to a host. But this shouldn't matter as
you should be able to use a PDA comm port (either with cable or bluetooth).
 
Hi Floyd,

I have a MDA II (in case you know this pda type) and the only cable I can
attach to it is the USB cable.
Would that work, if I use a USB to Serial device?

Regards
Rainer
 
Hi Joseph,

it is a MDA II

Regards
Rainer

Joseph Byrns said:
What model PDA is it? Usually PDAs have a physical RS232 option via an
RS232 cable.


so in this case the PC is the USB host, PDAs don't usually have the
ability to be the USB host only to connect to a host. But this shouldn't
matter as you should be able to use a PDA comm port (either with cable or
bluetooth).
Click to expand...
 
If you connect with the cable to your PC, your device is *not* acting as a
USB host. That is, you can't plug in a, say, USB flash drive, to your PDA,
because it's designed to be a device itself, not to connect to devices. If
that's the only USB connection your device has and if the peripheral you're
trying to connect to can connect to a PC with a similar cable, you'll have
to find another way, as Chris said.

Paul T.
 
The PDA to PC is a function connection. You can't use that for RS232.
You'd need a Host port (if you can plug in a USB mouse or keyboard, you have
host support).

Most PPCs have a direct RS232 UART though, so why not use that?

--
Chris Tacke
Co-founder
OpenNETCF.org
Are you using the SDF? Let's do a case study.
Email us at d c s @ o p e n n e t c f . c o m
http://www.opennetcf.org/donate
 
Hi Chris,

thanks for responding.

Well my pda is a MDA II and unforunately has no direct rs232 port.
As a cable connection it only has the USB which - as I have to accept -
is not usable as a USB_host :-(
So for my little project I have to either find a pda with a rs2232 or use
blue tooth.... hm...

Regards
Rainer
 
Hi Paul,

thanks for the information.
So for my project I have to either find a pda with rs232 or use blue tooth
(how ever that can bee achieved).

Regards
Rainer
 
Maybe there's some other way, but you're the only one who's going to be able
to answer that question. Why this particular PDA? Why this particular?
Why this microcontroller? You're the only one who knows where your
flexibility is...

Paul T.
 
Hi Paul,

yes, I have to do some more (re-)search on this subject.
The "why"s...
this particular PDA-> because my customer is using this paticular one.
" microcontroller -> customer again ;-)
..... and again .. the customer.

May be I can convince my customer to walk into a different way ..
pda...control... ? We will see.
Thanks for your answers.

Rainer
 
You seem to be getting mixed up between the USB and RS232. They are both
completely separate and you do not need to concern yourself with USB. Using
the cable in the link I sent (and likely the one in your link) you will be
able to communcate using serial comms, (it will likely appear as comm1 to
your program).
 
Hi Joseph,

that is good news!
The more I think about it, I think you are right :-))
I will get me this cable and them make some tests.
It looks like my project reduces to pda->rs232 !

Thanks
Rainer
 
So, then you're stuck. Unless the USB port on the PDA can be used as a host
or supports USB On-the-go, which would allow it to act as either end of the
connection, depending on the context, you'll have to go bluetooth, I think.

Paul T.

Rainer Queck said:
Hi Paul,

yes, I have to do some more (re-)search on this subject.
The "why"s...
this particular PDA-> because my customer is using this paticular one.
" microcontroller -> customer again ;-)
.... and again .. the customer.

May be I can convince my customer to walk into a different way ..
pda...control... ? We will see.
Thanks for your answers.

Rainer

Paul G. Tobey said:
Maybe there's some other way, but you're the only one who's going to be
able to answer that question. Why this particular PDA? Why this
particular? Why this microcontroller? You're the only one who knows
where your flexibility is...

Paul T.

Rainer Queck said:
Hi Paul,

thanks for the information.
So for my project I have to either find a pda with rs232 or use blue
tooth (how ever that can bee achieved).

Regards
Rainer

"Paul G. Tobey [eMVP]" <ptobey no spam AT no instrument no spam DOT com>
schrieb im Newsbeitrag If you connect with the cable to your PC, your device is *not* acting
as a USB host. That is, you can't plug in a, say, USB flash drive, to
your PDA, because it's designed to be a device itself, not to connect
to devices. If that's the only USB connection your device has and if
the peripheral you're trying to connect to can connect to a PC with a
similar cable, you'll have to find another way, as Chris said.

Paul T.

Hi Floyd,

I have a MDA II (in case you know this pda type) and the only cable I
can attach to it is the USB cable.
Would that work, if I use a USB to Serial device?

Regards
Rainer

Most of the PDAs have a separate cable that is used (generally) with
ActiveSync over serial. Those cables can be used for general serial
port stuff. FWIR, the RS232 connection is usually nulled, so it will
work when connecting to a computer, but you'd need to de-null it to
work with other devices (GPS, modems, etc)

--
Floyd

Hi Chris,

I never digged into USB theory, so am not sure, about
"USB_HOST_capability".
My pda is hooked up to my pc by a usb connecton.
So, you don't think that it is possible do comunicate with a pda via
usb/RS232 to a microcontroller?

Regards
Rainer

"<ctacke/>" <ctacke_AT_OpenNETCF_com> schrieb im Newsbeitrag
Your PDA has USB _Host_ capability? That's very unusual.

-Chris

Hi NG,

I have a little project to do.
I need to "talk" to a microcontroller device (RS232) from a pda
(wich only has USB) .
This program is to be developed with C# using VS2005 professional
(as soon as I get it delivered).

Since I have no idea on how to approach this project (yet), I very
much appreciate any hints, links and help on how to get started.

Thanks in advance
Rainer Queck
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