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Bluetooth transciever in metal box - how to expose antenna?
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P E Schoen
Feb 28, 2013, 7:46:47 PM2/28/13
to
I am considering adding Bluetooth to a piece of test equipment I am
designing. I am not really very familiar with it, but it seems to be pretty
easy to implement by connecting a transciever module to the microcontroller
RX/TX lines and having the PC find it and then using it as a wireless serial
port. I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
$12) and I ordered a module for the PIC controller of the test set:
http://www.ebay.com/itm/181072994083
Specs:
http://cxem.net/arduino/download/HC%20Serial%20Bluetooth%20Products%20201104.pdf
I'm fairly sure it will not work encased in an aluminum box with a 1/8"
aluminum panel, although possibly the signal could get in and out through
some openings that are locked only by an LCD display and other components. I
will probably need to expose the antenna, or add one that might even be
incorporated into the panel overlay which has a membrane keypad. We may need
to redesign the panel and perhaps an antenna could be added, but otherwise
(and for the prototype), perhaps I can just cut a rectangular slot for the
antenna portion of the PCB to be exposed, and maybe add a plastic cover to
protect it.
Has anyone had any experience with these modules, or others, and
specifically using them in a metal enclosure?
And is it possible to use the WiFi controller built into the PC (Toshiba
Satellite C655) for Bluetooth?
I did not find any Bluetooth adapters in Device Mangler and when I plugged
in the USB adapter it enumerated and installed automagically. But I don't
have any Bluetooth devices to test it with.
It installed as follows:
(Bluetooth Radios)
Broadcom BCM20702 Bluetooth 4.0 USB Device
Microsoft Bluetooth Enumerator
(Network Adapters)
Bluetooth Device (Personal Area Network)
Bluetooth Device (RFCOMM Protocol TDI)
I don't see it listed as a COM port, but maybe it first needs to be paired
with a slave device.
Thanks,
Paul
designing. I am not really very familiar with it, but it seems to be pretty
easy to implement by connecting a transciever module to the microcontroller
RX/TX lines and having the PC find it and then using it as a wireless serial
port. I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
$12) and I ordered a module for the PIC controller of the test set:
http://www.ebay.com/itm/181072994083
Specs:
http://cxem.net/arduino/download/HC%20Serial%20Bluetooth%20Products%20201104.pdf
I'm fairly sure it will not work encased in an aluminum box with a 1/8"
aluminum panel, although possibly the signal could get in and out through
some openings that are locked only by an LCD display and other components. I
will probably need to expose the antenna, or add one that might even be
incorporated into the panel overlay which has a membrane keypad. We may need
to redesign the panel and perhaps an antenna could be added, but otherwise
(and for the prototype), perhaps I can just cut a rectangular slot for the
antenna portion of the PCB to be exposed, and maybe add a plastic cover to
protect it.
Has anyone had any experience with these modules, or others, and
specifically using them in a metal enclosure?
And is it possible to use the WiFi controller built into the PC (Toshiba
Satellite C655) for Bluetooth?
I did not find any Bluetooth adapters in Device Mangler and when I plugged
in the USB adapter it enumerated and installed automagically. But I don't
have any Bluetooth devices to test it with.
It installed as follows:
(Bluetooth Radios)
Broadcom BCM20702 Bluetooth 4.0 USB Device
Microsoft Bluetooth Enumerator
(Network Adapters)
Bluetooth Device (Personal Area Network)
Bluetooth Device (RFCOMM Protocol TDI)
I don't see it listed as a COM port, but maybe it first needs to be paired
with a slave device.
Thanks,
Paul
Dave Platt
Feb 28, 2013, 7:59:34 PM2/28/13
to
>I'm fairly sure it will not work encased in an aluminum box with a 1/8"
>aluminum panel, although possibly the signal could get in and out through
>some openings that are locked only by an LCD display and other components.
It would probably not work at all well, if it works at all.
>aluminum panel, although possibly the signal could get in and out through
>some openings that are locked only by an LCD display and other components.
Take a look at
http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snoa519a&fileType=pdf
for some ideas. You might be able to incorporate a "printed inverted
F" antenna into one of the panels or overlays.
>And is it possible to use the WiFi controller built into the PC (Toshiba
>Satellite C655) for Bluetooth?
chipsets which do support both WiFi and Bluetooth, but that doesn't
appear to be the case for the WiFi interface in the C655 (Toshiba's
page says "No Bluetooth, no antenna").
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Nico Coesel
Feb 28, 2013, 8:29:27 PM2/28/13
to
"P E Schoen" <pa...@peschoen.com> wrote:
>I am considering adding Bluetooth to a piece of test equipment I am=20
>designing. I am not really very familiar with it, but it seems to be =
>pretty=20
>easy to implement by connecting a transciever module to the =
>microcontroller=20
>RX/TX lines and having the PC find it and then using it as a wireless =
>serial=20
>port. I just purchased a little Bluetooth 4.0 USB dongle for the PC =
>(only=20
>104.pdf
>
>I'm fairly sure it will not work encased in an aluminum box with a 1/8"=20
>aluminum panel, although possibly the signal could get in and out =
>through=20
>some openings that are locked only by an LCD display and other =
>components. I=20
>will probably need to expose the antenna, or add one that might even be=20
>incorporated into the panel overlay which has a membrane keypad. We may =
>need=20
>to redesign the panel and perhaps an antenna could be added, but =
>otherwise=20
>(and for the prototype), perhaps I can just cut a rectangular slot for =
>the=20
>antenna portion of the PCB to be exposed, and maybe add a plastic cover =
>to=20
>protect it.
>
>Has anyone had any experience with these modules, or others, and=20
anyway. My experience with using Bluetooth is that you need to write a
lot of software around it to mitigate problems with lost pairings or
connections which won't disengage.
>And is it possible to use the WiFi controller built into the PC (Toshiba =
>
>Satellite C655) for Bluetooth?
No. Bluetooth is not Wifi
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
>I am considering adding Bluetooth to a piece of test equipment I am=20
>designing. I am not really very familiar with it, but it seems to be =
>pretty=20
>easy to implement by connecting a transciever module to the =
>microcontroller=20
>RX/TX lines and having the PC find it and then using it as a wireless =
>serial=20
>port. I just purchased a little Bluetooth 4.0 USB dongle for the PC =
>(only=20
>$12) and I ordered a module for the PIC controller of the test set:
>http://www.ebay.com/itm/181072994083
>Specs:
>http://cxem.net/arduino/download/HC%20Serial%20Bluetooth%20Products%20201=
>http://www.ebay.com/itm/181072994083
>Specs:
>104.pdf
>
>I'm fairly sure it will not work encased in an aluminum box with a 1/8"=20
>aluminum panel, although possibly the signal could get in and out =
>through=20
>some openings that are locked only by an LCD display and other =
>components. I=20
>will probably need to expose the antenna, or add one that might even be=20
>incorporated into the panel overlay which has a membrane keypad. We may =
>need=20
>to redesign the panel and perhaps an antenna could be added, but =
>otherwise=20
>(and for the prototype), perhaps I can just cut a rectangular slot for =
>the=20
>antenna portion of the PCB to be exposed, and maybe add a plastic cover =
>to=20
>protect it.
>
>Has anyone had any experience with these modules, or others, and=20
>specifically using them in a metal enclosure?
A metal enclosure is a no-go. Otherwise most modules are complete crap
anyway. My experience with using Bluetooth is that you need to write a
lot of software around it to mitigate problems with lost pairings or
connections which won't disengage.
>And is it possible to use the WiFi controller built into the PC (Toshiba =
>
>Satellite C655) for Bluetooth?
No. Bluetooth is not Wifi
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
bloggs.fred...@gmail.com
Feb 28, 2013, 8:56:09 PM2/28/13
to
P E Schoen
Feb 28, 2013, 9:21:29 PM2/28/13
to
"Dave Platt" wrote in message news:m4b50a-...@radagast.org...
> It would probably not work at all well, if it works at all.
> Take a look at
>
> http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snoa519a&fileType=pdf
> for some ideas. You might be able to incorporate a "printed
> inverted F" antenna into one of the panels or overlays.
Good information. It seems that possibly a vertical antenna may be best,
something like the following which is similar to that on some walkie-talkies
and routers:
<http://www.mouser.com/ProductDetail/Roving-Networks/RN-SMA-4/?qs=sGAEpiMZZMtqO%252bWUGLBzeAlOUaKrl2Gg>
It's a little expensive at $7 but this is for a $3000 test set and the
Bluetooth option could easily be a $200 adder. Maybe a female SMA connector
can be mounted on the panel and connect to the module with a 50 ohm coax
cable:
<http://www.mouser.com/ProductDetail/TE-Connectivity-AMP/SMA-JS-P2-S/?qs=sGAEpiMZZMuLQf%252bEuFsOrnl3T6JYQ6%252bUOJgMTAkJ4%252bo%3d>
<http://www.mouser.com/pdfdocs/TEConnectivity_KOAXXA_SMA_QRG_0112.pdf>
I might need to get a module that has an SMA connector for proper matching.
<http://www.mouser.com/ProductDetail/Roving-Networks/RN24E-I-RM/?qs=sGAEpiMZZMtqO%252bWUGLBzeHWBrVBExf6F>
<http://www.mouser.com/ds/2/349/Bluetooth-RN-24-DS-3184.pdf>
These modules are $53 each but are probably far superior to the cheap
Chinese versions at about $10.
Thanks for the ideas. I'll see how the module works when I get it in a few
days.
Paul
> It would probably not work at all well, if it works at all.
> Take a look at
>
> http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snoa519a&fileType=pdf
> for some ideas. You might be able to incorporate a "printed
> inverted F" antenna into one of the panels or overlays.
something like the following which is similar to that on some walkie-talkies
and routers:
<http://www.mouser.com/ProductDetail/Roving-Networks/RN-SMA-4/?qs=sGAEpiMZZMtqO%252bWUGLBzeAlOUaKrl2Gg>
It's a little expensive at $7 but this is for a $3000 test set and the
Bluetooth option could easily be a $200 adder. Maybe a female SMA connector
can be mounted on the panel and connect to the module with a 50 ohm coax
cable:
<http://www.mouser.com/ProductDetail/TE-Connectivity-AMP/SMA-JS-P2-S/?qs=sGAEpiMZZMuLQf%252bEuFsOrnl3T6JYQ6%252bUOJgMTAkJ4%252bo%3d>
<http://www.mouser.com/pdfdocs/TEConnectivity_KOAXXA_SMA_QRG_0112.pdf>
I might need to get a module that has an SMA connector for proper matching.
<http://www.mouser.com/ProductDetail/Roving-Networks/RN24E-I-RM/?qs=sGAEpiMZZMtqO%252bWUGLBzeHWBrVBExf6F>
<http://www.mouser.com/ds/2/349/Bluetooth-RN-24-DS-3184.pdf>
These modules are $53 each but are probably far superior to the cheap
Chinese versions at about $10.
Thanks for the ideas. I'll see how the module works when I get it in a few
days.
Paul
P E Schoen
Feb 28, 2013, 9:34:40 PM2/28/13
to
Another possibility that's only $15 (but needs a separate PCB):
http://www.mouser.com/ProductDetail/STMicroelectronics/SPBT2532C2AT/?qs=sGAEpiMZZMtcidiSkZ6c9l1w9yX5%252bTgz
http://www.mouser.com/ds/2/389/CD00243909-62079.pdf
Also has antenna details.
Paul
http://www.mouser.com/ProductDetail/STMicroelectronics/SPBT2532C2AT/?qs=sGAEpiMZZMtcidiSkZ6c9l1w9yX5%252bTgz
http://www.mouser.com/ds/2/389/CD00243909-62079.pdf
Also has antenna details.
Paul
Jeff Liebermann
Feb 28, 2013, 9:39:10 PM2/28/13
to
On Thu, 28 Feb 2013 19:46:47 -0500, "P E Schoen" <pa...@peschoen.com>
wrote:
>I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
>$12)
Which one?
>and I ordered a module for the PIC controller of the test set:
>http://www.ebay.com/itm/181072994083
>Specs:
>http://cxem.net/arduino/download/HC%20Serial%20Bluetooth%20Products%20201104.pdf
The antenna is the wiggly gold plated line at the far end of the PCB.
>I will probably need to expose the antenna, or add one that might even be
>incorporated into the panel overlay which has a membrane keypad.
(...)
you can find an area of the box, where you can insert
a plastic window, with a direct view of the wiggly gold plated
antenna, you should be ok. It will be highly directional, but at
least it will work on that side of the box.
You'll have to cut the trace to the wiggly gold plated antenna, and
solder the very tiny coax that usually comes with Wi-Fi antennas.
<http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
Or, you could just drill a hole, install a panel mount RP-SMA
receptacle, and screw in a variety of available wi-fi antennas.
>Has anyone had any experience with these modules, or others, and
>specifically using them in a metal enclosure?
I've had a little in the distant past. The client failed FCC Part 15
incidental radiation and decided to metalize the inside of the plastic
enclosure. Then, they were wondering why the BlueGoof range was
seriously lacking. I had to scrape off enough metalization to get a
2.4Ghz signal through, but not so big a hole that it would again fail
part 15. It was not fun.
>And is it possible to use the WiFi controller built into the PC (Toshiba
>Satellite C655) for Bluetooth?
No. Same frequency but radically different protocols. For example,
Wi-Fi is mostly direct sequence spread spectrum, while BlueGoof is
frequency hopping spread spectrum. There are some wireless boards
that will do both Wi-Fi and BlueGoof, but not simultaneously.
>I did not find any Bluetooth adapters in Device Mangler and when I plugged
>in the USB adapter it enumerated and installed automagically. But I don't
>have any Bluetooth devices to test it with.
If you have a smartphone, the BT section should be suitable for
testing your laptop dongle. Just make sure you set the smartphone to
be "visible" for pairing.
>It installed as follows:
>
>(Bluetooth Radios)
>Broadcom BCM20702 Bluetooth 4.0 USB Device
>Microsoft Bluetooth Enumerator
>
>(Network Adapters)
>Bluetooth Device (Personal Area Network)
>Bluetooth Device (RFCOMM Protocol TDI)
>
>I don't see it listed as a COM port, but maybe it first needs to be paired
>with a slave device.
You'll see a BT icon in the system tray on your laptop. Right click
and select something like "settings". There should be a tab for
selecting a COM port.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
>I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
>$12)
>and I ordered a module for the PIC controller of the test set:
>http://www.ebay.com/itm/181072994083
>Specs:
>http://cxem.net/arduino/download/HC%20Serial%20Bluetooth%20Products%20201104.pdf
>I will probably need to expose the antenna, or add one that might even be
>incorporated into the panel overlay which has a membrane keypad.
>We may need
>to redesign the panel and perhaps an antenna could be added, but otherwise
>(and for the prototype), perhaps I can just cut a rectangular slot for the
>antenna portion of the PCB to be exposed, and maybe add a plastic cover to
>protect it.
Putting your hand over the keyboard would block some of the signal. If
>to redesign the panel and perhaps an antenna could be added, but otherwise
>(and for the prototype), perhaps I can just cut a rectangular slot for the
>antenna portion of the PCB to be exposed, and maybe add a plastic cover to
>protect it.
you can find an area of the box, where you can insert
a plastic window, with a direct view of the wiggly gold plated
antenna, you should be ok. It will be highly directional, but at
least it will work on that side of the box.
You'll have to cut the trace to the wiggly gold plated antenna, and
solder the very tiny coax that usually comes with Wi-Fi antennas.
<http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
Or, you could just drill a hole, install a panel mount RP-SMA
receptacle, and screw in a variety of available wi-fi antennas.
>Has anyone had any experience with these modules, or others, and
>specifically using them in a metal enclosure?
incidental radiation and decided to metalize the inside of the plastic
enclosure. Then, they were wondering why the BlueGoof range was
seriously lacking. I had to scrape off enough metalization to get a
2.4Ghz signal through, but not so big a hole that it would again fail
part 15. It was not fun.
>And is it possible to use the WiFi controller built into the PC (Toshiba
>Satellite C655) for Bluetooth?
Wi-Fi is mostly direct sequence spread spectrum, while BlueGoof is
frequency hopping spread spectrum. There are some wireless boards
that will do both Wi-Fi and BlueGoof, but not simultaneously.
>I did not find any Bluetooth adapters in Device Mangler and when I plugged
>in the USB adapter it enumerated and installed automagically. But I don't
>have any Bluetooth devices to test it with.
testing your laptop dongle. Just make sure you set the smartphone to
be "visible" for pairing.
>It installed as follows:
>
>(Bluetooth Radios)
>Broadcom BCM20702 Bluetooth 4.0 USB Device
>Microsoft Bluetooth Enumerator
>
>(Network Adapters)
>Bluetooth Device (Personal Area Network)
>Bluetooth Device (RFCOMM Protocol TDI)
>
>I don't see it listed as a COM port, but maybe it first needs to be paired
>with a slave device.
and select something like "settings". There should be a tab for
selecting a COM port.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
P E Schoen
Feb 28, 2013, 10:32:50 PM2/28/13
to
"Jeff Liebermann" wrote in message
news:i340j8d43cb03d73t...@4ax.com...
> On Thu, 28 Feb 2013 19:46:47 -0500, "P E Schoen" <pa...@peschoen.com>
> wrote:
>> I just purchased a little Bluetooth 4.0 USB dongle for the PC
>>(only $12)
> Which one?
It's an IOGear Model GBU521
> You'll have to cut the trace to the wiggly gold plated antenna, and
> solder the very tiny coax that usually comes with Wi-Fi antennas.
> <http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
> Or, you could just drill a hole, install a panel mount RP-SMA
> receptacle, and screw in a variety of available wi-fi antennas.
That seems to be the best option for now.
>> Has anyone had any experience with these modules, or others, and
>> specifically using them in a metal enclosure?
> I've had a little in the distant past. The client failed FCC Part 15
> incidental radiation and decided to metalize the inside of the plastic
> enclosure. Then, they were wondering why the BlueGoof range was
> seriously lacking. I had to scrape off enough metalization to get a
> 2.4Ghz signal through, but not so big a hole that it would again fail
> part 15. It was not fun.
I suppose we should look into certification. Some of our test sets are used
in nuclear power plants and government installations where RFI may be a
problem.
>> I did not find any Bluetooth adapters in Device Mangler and when I
>> plugged in the USB adapter it enumerated and installed automagically.
>> But I don't have any Bluetooth devices to test it with.
> If you have a smartphone, the BT section should be suitable for
> testing your laptop dongle. Just make sure you set the smartphone
> to be "visible" for pairing.
I have an Archos 70 Internet Tablet which I powered up and it was found by
the PC and paired, although the Archos device indicated it was not
connected. I was not able to assign a COM port but I was able to send a file
from the PC to the device via Bluetooth. The devices were only inches apart
so it was not a good test of distance. But at least I know the dongle works.
The Bluetooth module may offer itself as a COM port.
> You'll see a BT icon in the system tray on your laptop. Right
> click and select something like "settings". There should be
> a tab for selecting a COM port.
That did not seem to work, but I was able to connect and send a file.
Thanks,
Paul
news:i340j8d43cb03d73t...@4ax.com...
> On Thu, 28 Feb 2013 19:46:47 -0500, "P E Schoen" <pa...@peschoen.com>
> wrote:
>> I just purchased a little Bluetooth 4.0 USB dongle for the PC
>>(only $12)
> Which one?
> You'll have to cut the trace to the wiggly gold plated antenna, and
> solder the very tiny coax that usually comes with Wi-Fi antennas.
> <http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
> Or, you could just drill a hole, install a panel mount RP-SMA
> receptacle, and screw in a variety of available wi-fi antennas.
>> Has anyone had any experience with these modules, or others, and
>> specifically using them in a metal enclosure?
> I've had a little in the distant past. The client failed FCC Part 15
> incidental radiation and decided to metalize the inside of the plastic
> enclosure. Then, they were wondering why the BlueGoof range was
> seriously lacking. I had to scrape off enough metalization to get a
> 2.4Ghz signal through, but not so big a hole that it would again fail
> part 15. It was not fun.
in nuclear power plants and government installations where RFI may be a
problem.
>> I did not find any Bluetooth adapters in Device Mangler and when I
>> plugged in the USB adapter it enumerated and installed automagically.
>> But I don't have any Bluetooth devices to test it with.
> If you have a smartphone, the BT section should be suitable for
> testing your laptop dongle. Just make sure you set the smartphone
> to be "visible" for pairing.
the PC and paired, although the Archos device indicated it was not
connected. I was not able to assign a COM port but I was able to send a file
from the PC to the device via Bluetooth. The devices were only inches apart
so it was not a good test of distance. But at least I know the dongle works.
The Bluetooth module may offer itself as a COM port.
> You'll see a BT icon in the system tray on your laptop. Right
> click and select something like "settings". There should be
> a tab for selecting a COM port.
Thanks,
Paul
John Walliker
Mar 1, 2013, 3:50:05 AM3/1/13
to
On Mar 1, 3:32 am, "P E Schoen" <p...@peschoen.com> wrote:
> >> Has anyone had any experience with these modules, or others, and
> >> specifically using them in a metal enclosure?
You might consider creating a slot antenna in the housing. This would
> >> Has anyone had any experience with these modules, or others, and
> >> specifically using them in a metal enclosure?
be
a fairly narrow slot aboiut 1/2 wavelength long and driven half way
along
on each side (from the inside). You might need a balun for best
results,
but even without one it could work well. (You need some free space
inside the slot as well as outside - or even better a reflecting plate
spaced
appropriately behind it.)
Another possibility is creating half-wave slots in the housing to let
the
signal out from an internal antenna. They would act as filters
letting
the BT signal (and harmonics) in and out. Ensure the polarisation
of the slots matches the internal antenna if possible. The slot
polarisation
is at right angles to that of a wire antenna.
Whatever antenna you use, try to keep it as far away from other
conductive materials as you can. An antenna is not just the wire or
slot. It also includes the space immediately around it. If that
space is
occupied, the antenna will lose efficiency or bandwidth. If it is a
ready-
made antenna it will be detuned.
Its hard to beat a quarter-wave monopole with a good ground plane and
plenty of space around it. Anything which tries to be smaller
inevitably
results in compromises on efficiency or bandwidth.
Narrow bandwidth means more risk that production variations or
environmental influences will detune the antenna giving a dramatic
fall
in output.
John
Uwe Hercksen
Mar 1, 2013, 7:01:00 AM3/1/13
to
P E Schoen schrieb:
> I have an Archos 70 Internet Tablet which I powered up and it was found
> by the PC and paired, although the Archos device indicated it was not
> connected. I was not able to assign a COM port but I was able to send a
> file from the PC to the device via Bluetooth. The devices were only
> inches apart so it was not a good test of distance. But at least I know
> the dongle works. The Bluetooth module may offer itself as a COM port.
I tried to connect a PC to a cell phone via Bluetooth, it did not work,
even over a very short distance of some inches. I had to switch of a
DECT wireless portable phone, than I could connect via Bluetooth.
Bluetooth uses very low transmitter power, but DECT uses much more power
and a frequency close to Bluetooth.
Bye
Boris Mohar
Mar 1, 2013, 9:03:33 AM3/1/13
to
>I am considering adding Bluetooth to a piece of test equipment I am
>designing. I am not really very familiar with it, but it seems to be pretty
>easy to implement by connecting a transciever module to the microcontroller
Slot antenna?
>designing. I am not really very familiar with it, but it seems to be pretty
>easy to implement by connecting a transciever module to the microcontroller
Regards,
Boris Mohar
Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
void _-void-_ in the obvious place
Jeff Liebermann
Mar 1, 2013, 10:36:05 AM3/1/13
to
On Thu, 28 Feb 2013 22:32:50 -0500, "P E Schoen" <pa...@peschoen.com>
BT 2.0 USB dongles for various abuses of the technology.
<http://www.ebay.com/itm/280804601979>
>> You'll have to cut the trace to the wiggly gold plated antenna, and
>> solder the very tiny coax that usually comes with Wi-Fi antennas.
>> <http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
>> Or, you could just drill a hole, install a panel mount RP-SMA
>> receptacle, and screw in a variety of available wi-fi antennas.
>
>That seems to be the best option for now.
It all depends on your construction. However, if you butcher the PCB,
you have effectively ruined one of the major benefits of buying a
ready to play BT module. It's pre-certified for FCC and generally
does not require that you recertify the BT radio. You'll probably
need to certify the rest of the instrument, but not the BT module. I
suggest you make every effort to use the module without modification
or find a more suitable module. Pre-certified modules will probably
NOT have a removable antenna or antenna connector, so modifications to
the metal case may be the only economical solution.
If the position of the PCB is not suitable for projecting through the
metal case, you can use a 1/2 wave slot as a passive re-radiator.
Orient the slot in exactly the same direction as the wiggly gold
antenna on the PCB and it will re-radiate some of the RF both in and
out. This is not as good as having the actual antenna exposed to the
outside via a plastic window, but might be sufficient. I'm not sure
how well this will work, but it's worth a try.
>I suppose we should look into certification. Some of our test sets are used
>in nuclear power plants and government installations where RFI may be a
>problem.
I don't know anything about nuclear power plants, but I presume they
are rather security conscious and RFI/EMI sensitive. Presumably, the
also look at certifications before buying instruments.
>I have an Archos 70 Internet Tablet which I powered up and it was found by
>the PC and paired, although the Archos device indicated it was not
>connected.
It's waiting for a password (usually 0000 or 1234).
>I was not able to assign a COM port but I was able to send a file
>from the PC to the device via Bluetooth. The devices were only inches apart
>so it was not a good test of distance. But at least I know the dongle works.
>The Bluetooth module may offer itself as a COM port.
It depends on which BT profiles are included with the device drivers
and config software:
<http://en.wikipedia.org/wiki/Bluetooth_profile>
Serial port emulation (SPP) profile is included with most everything
except audio devices. Since the RFCOMM driver was loaded, then you
should have serial port emulation installed. Check your BT settings
and options again.
wrote:
>"Jeff Liebermann" wrote in message
>news:i340j8d43cb03d73t...@4ax.com...
>
>> On Thu, 28 Feb 2013 19:46:47 -0500, "P E Schoen" <pa...@peschoen.com>
>> wrote:
>
>>> I just purchased a little Bluetooth 4.0 USB dongle for the PC
>>>(only $12)
>
>> Which one?
>
>It's an IOGear Model GBU521
You really don't need BT 4.0 for what you're doing. I use the $4/ea
>"Jeff Liebermann" wrote in message
>news:i340j8d43cb03d73t...@4ax.com...
>
>> On Thu, 28 Feb 2013 19:46:47 -0500, "P E Schoen" <pa...@peschoen.com>
>> wrote:
>
>>> I just purchased a little Bluetooth 4.0 USB dongle for the PC
>>>(only $12)
>
>> Which one?
>
>It's an IOGear Model GBU521
BT 2.0 USB dongles for various abuses of the technology.
<http://www.ebay.com/itm/280804601979>
>> You'll have to cut the trace to the wiggly gold plated antenna, and
>> solder the very tiny coax that usually comes with Wi-Fi antennas.
>> <http://802.11junk.com/jeffl/antennas/coaxial/slides/coax-ant.html>
>> Or, you could just drill a hole, install a panel mount RP-SMA
>> receptacle, and screw in a variety of available wi-fi antennas.
>
>That seems to be the best option for now.
you have effectively ruined one of the major benefits of buying a
ready to play BT module. It's pre-certified for FCC and generally
does not require that you recertify the BT radio. You'll probably
need to certify the rest of the instrument, but not the BT module. I
suggest you make every effort to use the module without modification
or find a more suitable module. Pre-certified modules will probably
NOT have a removable antenna or antenna connector, so modifications to
the metal case may be the only economical solution.
If the position of the PCB is not suitable for projecting through the
metal case, you can use a 1/2 wave slot as a passive re-radiator.
Orient the slot in exactly the same direction as the wiggly gold
antenna on the PCB and it will re-radiate some of the RF both in and
out. This is not as good as having the actual antenna exposed to the
outside via a plastic window, but might be sufficient. I'm not sure
how well this will work, but it's worth a try.
>I suppose we should look into certification. Some of our test sets are used
>in nuclear power plants and government installations where RFI may be a
>problem.
are rather security conscious and RFI/EMI sensitive. Presumably, the
also look at certifications before buying instruments.
>I have an Archos 70 Internet Tablet which I powered up and it was found by
>the PC and paired, although the Archos device indicated it was not
>connected.
>I was not able to assign a COM port but I was able to send a file
>from the PC to the device via Bluetooth. The devices were only inches apart
>so it was not a good test of distance. But at least I know the dongle works.
>The Bluetooth module may offer itself as a COM port.
and config software:
<http://en.wikipedia.org/wiki/Bluetooth_profile>
Serial port emulation (SPP) profile is included with most everything
except audio devices. Since the RFCOMM driver was loaded, then you
should have serial port emulation installed. Check your BT settings
and options again.
whit3rd
Mar 1, 2013, 1:12:13 PM3/1/13
to
On Thursday, February 28, 2013 4:46:47 PM UTC-8, P E Schoen wrote:
> I am considering adding Bluetooth to a piece of test equipment I am
> designing. I am not really very familiar with it, but it seems to be pretty
> easy to implement by connecting a transciever module to the microcontroller
> RX/TX lines and having the PC find it and then using it as a wireless serial
> port. I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
> $12)
Well, if you can put a USB socket somewhere on your test equipment,
> I am considering adding Bluetooth to a piece of test equipment I am
> designing. I am not really very familiar with it, but it seems to be pretty
> easy to implement by connecting a transciever module to the microcontroller
> RX/TX lines and having the PC find it and then using it as a wireless serial
> port. I just purchased a little Bluetooth 4.0 USB dongle for the PC (only
> $12)
there's a $12 solution for you.
I've seen some bluetooth for PCs done as a USB cable, to a molded
plastic blob that attaches outside the case, under a piece of plastic
trim, with its cable snake-ing through a perforation and plugging into
one of the USB headers.
P E Schoen
Mar 1, 2013, 7:29:33 PM3/1/13
to
"whit3rd" wrote in message
news:9caf1eaa-1025-47ce...@googlegroups.com...
> Well, if you can put a USB socket somewhere on your test equipment,
> there's a $12 solution for you.
> I've seen some bluetooth for PCs done as a USB cable, to a molded
> plastic blob that attaches outside the case, under a piece of plastic
> trim, with its cable snake-ing through a perforation and plugging into
> one of the USB headers.
The USB bluetooth for PCs is not the same as that for a slave device. I have
USB implemented on the instrument PCB but it is not configured as a host. It
may be possible to use USB OTG to do that, but I think it will involve a lot
more than just connecting a module to the RX/TX lines of the processor.
There are modules with an antenna and a cable for under $20 that should take
care of the issues.
http://www.ebay.com/itm/271109056178
Thanks,
Paul
news:9caf1eaa-1025-47ce...@googlegroups.com...
> Well, if you can put a USB socket somewhere on your test equipment,
> there's a $12 solution for you.
> I've seen some bluetooth for PCs done as a USB cable, to a molded
> plastic blob that attaches outside the case, under a piece of plastic
> trim, with its cable snake-ing through a perforation and plugging into
> one of the USB headers.
USB implemented on the instrument PCB but it is not configured as a host. It
may be possible to use USB OTG to do that, but I think it will involve a lot
more than just connecting a module to the RX/TX lines of the processor.
There are modules with an antenna and a cable for under $20 that should take
care of the issues.
http://www.ebay.com/itm/271109056178
Thanks,
Paul
P E Schoen
Mar 3, 2013, 2:36:43 AM3/3/13
to
Just as an update, I received the Bluetooth module
http://www.ebay.com/itm/181072994083 in the mail on Saturday and I was able
to connect it to a PIC project which reads four ADC channels and transmits
the values every 5 seconds at 9600,N,8,1, which happens to be the default
for the module. I had already installed the Bluetooth USB dongle on my
laptop and paired it with my Archos 70 tablet and was able to send a file.
It did not appear to have a COM port as a service.
The module on the datalogger was discovered and drivers were automagically
installed and it showed that COM14 was available. I chose that in my TTYdemo
application and it worked a charm. I was unable to block the transmission by
cupping my hand around the module, and even a 7"x9" 12 gauge steel plate did
not interrupt the data stream. So I think it may be enough to expose just
the 1/4" x 1/2" x 1/16" PCB antenna through a slot in the panel, perhaps
protected by a small plastic piece.
I'm happily amazed at the simplicity and low cost (under $20) of
implementing this technology. It may be a big selling point to be able to
control and read data from the test set using a laptop computer or even a
tablet device or smart phone. Maybe even make a detachable keypad with
Bluetooth on both ends. This may be much more practical than my previous
idea of implementing an Ethernet and WiFi connection where the test set
would appear as a web page with an HTML keypad. It's cool to be able to
control the device and read data from anywhere in the world over the
internet, but it's really not necessary and may present security and safety
issues.
But now I need to figure out how to program the equivalent of a keypad and
display on the tablet device. The Archos 70 is an Android device and I
didn't have any luck making an App with the DTK and Windows emulator. Maybe
it will be easier to get a Win7 tablet where the same App will work on a
laptop or hand held device, and I won't need to learn a new OS.
Thanks,
Paul
http://www.ebay.com/itm/181072994083 in the mail on Saturday and I was able
to connect it to a PIC project which reads four ADC channels and transmits
the values every 5 seconds at 9600,N,8,1, which happens to be the default
for the module. I had already installed the Bluetooth USB dongle on my
laptop and paired it with my Archos 70 tablet and was able to send a file.
It did not appear to have a COM port as a service.
The module on the datalogger was discovered and drivers were automagically
installed and it showed that COM14 was available. I chose that in my TTYdemo
application and it worked a charm. I was unable to block the transmission by
cupping my hand around the module, and even a 7"x9" 12 gauge steel plate did
not interrupt the data stream. So I think it may be enough to expose just
the 1/4" x 1/2" x 1/16" PCB antenna through a slot in the panel, perhaps
protected by a small plastic piece.
I'm happily amazed at the simplicity and low cost (under $20) of
implementing this technology. It may be a big selling point to be able to
control and read data from the test set using a laptop computer or even a
tablet device or smart phone. Maybe even make a detachable keypad with
Bluetooth on both ends. This may be much more practical than my previous
idea of implementing an Ethernet and WiFi connection where the test set
would appear as a web page with an HTML keypad. It's cool to be able to
control the device and read data from anywhere in the world over the
internet, but it's really not necessary and may present security and safety
issues.
But now I need to figure out how to program the equivalent of a keypad and
display on the tablet device. The Archos 70 is an Android device and I
didn't have any luck making an App with the DTK and Windows emulator. Maybe
it will be easier to get a Win7 tablet where the same App will work on a
laptop or hand held device, and I won't need to learn a new OS.
Thanks,
Paul
P E Schoen
Mar 21, 2013, 5:52:15 PM3/21/13
to
Another update :)
I have the Bluetooth module installed on a PC board in my PI-250 test set,
connected to the RXD and TXD lines of a PIC18F4455, and I was able to
establish communication. I received a stream of text data at 300 mSec
intervals, and I was able to initiate, stop, and reset the unit by clicking
the I, S, and R keys in a terminal emulator (TTY.exe) similar to Hyperterm,
but using a Delphi Comm driver.
I put the unit into its aluminum enclosure, and the communication was still
working. I moved my laptop computer to another room, about 20 feet away,
behind two closed doors, and although it seemed to be a little sketchy, it
still worked.
So, I probably won't need any sort of exposed antenna, and probably just a
small plastic-covered opening with the PCB antenna just below it, will allow
reliable operation. I will need to test it in noisy environments such as
will often be encountered in normal use. There may be RFI sources such as
welders, hipot testers, and circuit breaker test equipment running up to
50kA from time to time. But this Bluetooth feature is just a proposed option
and will be used mostly for data collection where a miscommunication would
only require resending the data. It would be more serious if the unit could
be inadvertently initiated.
I'm very impressed with this technology, especially when it is available at
such low cost and with such simple implementation.
Paul
I have the Bluetooth module installed on a PC board in my PI-250 test set,
connected to the RXD and TXD lines of a PIC18F4455, and I was able to
establish communication. I received a stream of text data at 300 mSec
intervals, and I was able to initiate, stop, and reset the unit by clicking
the I, S, and R keys in a terminal emulator (TTY.exe) similar to Hyperterm,
but using a Delphi Comm driver.
I put the unit into its aluminum enclosure, and the communication was still
working. I moved my laptop computer to another room, about 20 feet away,
behind two closed doors, and although it seemed to be a little sketchy, it
still worked.
So, I probably won't need any sort of exposed antenna, and probably just a
small plastic-covered opening with the PCB antenna just below it, will allow
reliable operation. I will need to test it in noisy environments such as
will often be encountered in normal use. There may be RFI sources such as
welders, hipot testers, and circuit breaker test equipment running up to
50kA from time to time. But this Bluetooth feature is just a proposed option
and will be used mostly for data collection where a miscommunication would
only require resending the data. It would be more serious if the unit could
be inadvertently initiated.
I'm very impressed with this technology, especially when it is available at
such low cost and with such simple implementation.
Paul
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