Bluetooth 2 Module
Bluetooth 2 Module
by inaki
Thu Apr 13, 2006 1:23 pm
I am working in a Bluetooth 2 interface at 3Mbps. My first target, for now will be the KHR1, and then the Robotis Kit (or perhaps the other way 
).
As I have to order a very specific PCB mount for the BT2 module in quantity I wonder if anyone would be interested in this kind of interface for his own development ? It would be independent of the specific controller used (I use a specific controller). In other words, it is a BT2 module mounted on a standard PCB with a standard connector.
If anyone wants one (or more) of these please leave me an email.
).
As I have to order a very specific PCB mount for the BT2 module in quantity I wonder if anyone would be interested in this kind of interface for his own development ? It would be independent of the specific controller used (I use a specific controller). In other words, it is a BT2 module mounted on a standard PCB with a standard connector.
If anyone wants one (or more) of these please leave me an email.
by Meltdown
Fri Apr 14, 2006 11:04 pm
I'm heavily looking into this as well.
Reading up on all the specs on the oem ones.
What brand of BT module are you talking about?
What will it cost? Dimensions?
Uart only or Uart and usb?
Operation voltage?
I've seen several ones by now. The cheapest one being 50 dollars.
The problem for me is the high shipping costs to the Netherlands.
There's even one that charges an outragious $200 shipping!
Reading up on all the specs on the oem ones.
What brand of BT module are you talking about?
What will it cost? Dimensions?
Uart only or Uart and usb?
Operation voltage?
I've seen several ones by now. The cheapest one being 50 dollars.
The problem for me is the high shipping costs to the Netherlands.
There's even one that charges an outragious $200 shipping!
by inaki
Sat Apr 15, 2006 12:50 pm
Hi Meltdown!
The module is the WT11 from BlueGiga.
http://www.bluegiga.com/default.asp?f=2 ... 0&subp=200
It is UART and USB.
The soldering is very difficult to do without oven so I have ordered a custom PCB board with a standard connector with the module already mounted. This way the final board is slightly larger than the module itself. The module is 35x14 mm. The PCB board manufacturing and mounting is performed here in Spain.
The version I have bought is the one with integrated antenna. There is another with external antena though. With integrated antenna the reach is about 60m.
Voltage: 3.3 V
The cost will be the cost of the module itself (about $50) plus the cost of the PCB and mounting, plus shipping (from Spain). I would estimate less than $100, shipping included. I will have the exact prices next week.
The module is the WT11 from BlueGiga.
http://www.bluegiga.com/default.asp?f=2 ... 0&subp=200
It is UART and USB.
The soldering is very difficult to do without oven so I have ordered a custom PCB board with a standard connector with the module already mounted. This way the final board is slightly larger than the module itself. The module is 35x14 mm. The PCB board manufacturing and mounting is performed here in Spain.
The version I have bought is the one with integrated antenna. There is another with external antena though. With integrated antenna the reach is about 60m.
Voltage: 3.3 V
The cost will be the cost of the module itself (about $50) plus the cost of the PCB and mounting, plus shipping (from Spain). I would estimate less than $100, shipping included. I will have the exact prices next week.
by Meltdown
Sun Apr 16, 2006 1:45 pm
Hi Inaki,
I'm interested.
The custom pcb bit isn't to clear to me yet.
Does it contain an rs232 9 pin connector?
Soldering isn't a problem for me because i'm used to solder tiny smd
parts.
I was/am tempted to buy this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... Track=true.
What do you think of that one?
Let me know as soon as you know the final costs.
I'm interested.
The custom pcb bit isn't to clear to me yet.
Does it contain an rs232 9 pin connector?
Soldering isn't a problem for me because i'm used to solder tiny smd
parts.
I was/am tempted to buy this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... Track=true.
What do you think of that one?
Let me know as soon as you know the final costs.
by inaki
Tue Apr 18, 2006 12:02 pm
Meltdown, the PCB connector is a standard mini-header type, it is not an RS232 because there are other signals in it, besides the serial lines.
I was unable to perform the soldering of the module despite I am used to solder. Actually the PCB prevents you from soldering. If you think you are able to use the module 'as is' I would not recommend to purchase this PCB. Would be of not use for you.
In case you are interested there is also a mini development kit board that has serial and USB connectors. It is much cheaper than the expensive kit offered by BlueGiga that costs $750.
Regarding the module you mention on eBay. It is a regular Bluetooth USB module, right? It is not Bluetooth 2.
I was unable to perform the soldering of the module despite I am used to solder. Actually the PCB prevents you from soldering. If you think you are able to use the module 'as is' I would not recommend to purchase this PCB. Would be of not use for you.
In case you are interested there is also a mini development kit board that has serial and USB connectors. It is much cheaper than the expensive kit offered by BlueGiga that costs $750.
Regarding the module you mention on eBay. It is a regular Bluetooth USB module, right? It is not Bluetooth 2.
by Meltdown
Wed Apr 19, 2006 3:09 am
That's to bad.
I need a rs232 one, or a oem type which is easily converted into rs232.
The one on eBay is not a regular usb type.
It's a rs232 serial bluetooth adapter.
This one should work right out of the box with the KHR-1.
What i'd like to know is that most of the oem types have a uart with
rx, tx, cts and rts lines on ttl level.
Can ttl level directly be connected to the rs232 port of a computer or
do you have to transform the signals first through some kind of logic chip?
Looking at some of the developer pcb's it seems that some kind of chip is
used right after the rs232 connector.
I need a rs232 one, or a oem type which is easily converted into rs232.
The one on eBay is not a regular usb type.
It's a rs232 serial bluetooth adapter.
This one should work right out of the box with the KHR-1.
What i'd like to know is that most of the oem types have a uart with
rx, tx, cts and rts lines on ttl level.
Can ttl level directly be connected to the rs232 port of a computer or
do you have to transform the signals first through some kind of logic chip?
Looking at some of the developer pcb's it seems that some kind of chip is
used right after the rs232 connector.
by inaki
Wed Apr 19, 2006 9:05 am
The WT11 does have these RS232 lines too: RX,TX,etc. But the module also allows for USB, GPIO, SPI, etc so there are a lot of extra pins ( 28 in total ). You need a connector adapter to use a standard serial connector but it would be pretty easy to make.
Yes these serial devices have TTL levels that you must convert to RS232 levels if you connect them to a PC. The chip used by most people to perform this conversion is the MAX232. There is an easier version to interface called MAX233. Both are made by Maxim and can be found in any electronics store. They are cheap too.
Yes these serial devices have TTL levels that you must convert to RS232 levels if you connect them to a PC. The chip used by most people to perform this conversion is the MAX232. There is an easier version to interface called MAX233. Both are made by Maxim and can be found in any electronics store. They are cheap too.
by inaki
Wed Apr 19, 2006 4:36 pm
An addendum to my last post:
the serial lines available on WT11 are:
RX
TX
RTS
CTS
Note that DTR is not available. This signal,DTR, is needed on KHR1 to read data (for example to read position data). I think RTS and CTS are not used by KHR so you might probably replace the DTR signal with RTS or CTS but I have not tried this. Another solution that might work would be to keep DTR signal low all the time.
the serial lines available on WT11 are:
RX
TX
RTS
CTS
Note that DTR is not available. This signal,DTR, is needed on KHR1 to read data (for example to read position data). I think RTS and CTS are not used by KHR so you might probably replace the DTR signal with RTS or CTS but I have not tried this. Another solution that might work would be to keep DTR signal low all the time.
by Meltdown
Thu Apr 20, 2006 2:16 pm
Thanks for this invaluable info Inaki!
Yes the missing DTR signal is what's worrying me.
The KHR-1 rcs connector is connected this way:
pin 1 DCD - not connected
pin 2 TxD - white cable
pin 3 RxD - red cable
pin 4 DTR - connected with 2.2kohms resistor and bridged to pin 2
pin 5 - connected to earth with black cable
pin 6 DSR - not connected
pin 7 RTS - bridged with pin 8
pin 8 CTS - bridged with pin 7
pin 9 RI - not connected
Now pin 7 andd 8 are bridged (rts, cts).
It seems that rts and cts are used for something but what?
The problem i'm facing is that i can get a BT serial adapter that,
when i specificly specify the order, can use either CTS/RTS or DTR/DSR.
I'm not sure what to do because it seems that the KHR-1 needs both options.
You seem to know more of this than i do.
I appreciate any help you can give me.
Yes the missing DTR signal is what's worrying me.
The KHR-1 rcs connector is connected this way:
pin 1 DCD - not connected
pin 2 TxD - white cable
pin 3 RxD - red cable
pin 4 DTR - connected with 2.2kohms resistor and bridged to pin 2
pin 5 - connected to earth with black cable
pin 6 DSR - not connected
pin 7 RTS - bridged with pin 8
pin 8 CTS - bridged with pin 7
pin 9 RI - not connected
Now pin 7 andd 8 are bridged (rts, cts).
It seems that rts and cts are used for something but what?
The problem i'm facing is that i can get a BT serial adapter that,
when i specificly specify the order, can use either CTS/RTS or DTR/DSR.
I'm not sure what to do because it seems that the KHR-1 needs both options.
You seem to know more of this than i do.
I appreciate any help you can give me.
by inaki
Thu Apr 20, 2006 4:17 pm
Anyway I am going to order 6 units of the WT11 (with PCB). In case I get any success with KHR1 I will tell you (and sure I will have some modules to be shared). The DTR signal might perhaps be replaced by CTS/RTS signals but I am not positive of this.
Actually I am going to replace the RCB1 board with my own controller so I am not concerned specially about the RCB1 being compatible with this Bluetooth module but I would like to be able to use the RCB1 as well.
I receive the PCBs this week. I will check the DTR issue and see what happens.
CTS and RTS bridged means that the interface does not care about a posssible hardware flow control. This is not good for a general purpose interface.
Actually I am going to replace the RCB1 board with my own controller so I am not concerned specially about the RCB1 being compatible with this Bluetooth module but I would like to be able to use the RCB1 as well.
I receive the PCBs this week. I will check the DTR issue and see what happens.
CTS and RTS bridged means that the interface does not care about a posssible hardware flow control. This is not good for a general purpose interface.
by Meltdown
Fri Apr 21, 2006 8:26 pm
Thanks!
I've got it to work perfectly!
Tutorial
Changes you have to make in the ICS RS232 connector when using
a bluetooth module without DTR connection:
First you have to seperate the bridge on pin 7 and 8 (rts/cts)
Remove the resistor on pin 4 and bridge it to pin 8
So the resistor is now bridged between pin 2 and 8.
The com port must be set to: DTR tracks CTS.
If you don't it will still work but then you have to confirm some
functions twice, ie in teaching mode you have to double-click the OK
button instead of once.
That's it!
I've got it to work perfectly!
Tutorial
Changes you have to make in the ICS RS232 connector when using
a bluetooth module without DTR connection:
First you have to seperate the bridge on pin 7 and 8 (rts/cts)
Remove the resistor on pin 4 and bridge it to pin 8
So the resistor is now bridged between pin 2 and 8.
The com port must be set to: DTR tracks CTS.
If you don't it will still work but then you have to confirm some
functions twice, ie in teaching mode you have to double-click the OK
button instead of once.
That's it!
Last edited by Meltdown on Sat Apr 22, 2006 11:36 pm, edited 1 time in total.
by Meltdown
Mon Apr 24, 2006 12:58 pm
It was a test with the original rs232 ICS connector.
To see if, when rewired/re-routed, all the functions would still be working.
And it works flawlessly.
So i see no reason why it won't work with any bluetooth module
missing a DTR line.
I ordered the one i mentioned earlier from eBay.
It has some important advantages:
+5v to 9v operation instead of 3.3v so you can connect it without any modifications.
Inbuild antenna with the option (included) of an remote antenna.
Rs232 connector already implemented.
When it arrives i will report back.
If it works as advertised you can have wireless KHR-1 operation for
some $75 inc shipping.
Not bad at all.
Thanks for the great help Inaki!
To see if, when rewired/re-routed, all the functions would still be working.
And it works flawlessly.
So i see no reason why it won't work with any bluetooth module
missing a DTR line.
I ordered the one i mentioned earlier from eBay.
It has some important advantages:
+5v to 9v operation instead of 3.3v so you can connect it without any modifications.
Inbuild antenna with the option (included) of an remote antenna.
Rs232 connector already implemented.
When it arrives i will report back.
If it works as advertised you can have wireless KHR-1 operation for
some $75 inc shipping.
Not bad at all.
Thanks for the great help Inaki!
by Meltdown
Mon May 15, 2006 8:55 pm
Hi Inaki,
Go here: http://robosavvy.com/modules.php?name=F ... =1456#1456
Any bluetooth problems with the KHR-1 will be solved.
Go here: http://robosavvy.com/modules.php?name=F ... =1456#1456
Any bluetooth problems with the KHR-1 will be solved.