I recently bought this cheap Serial Port Bluetooth With ExpansionBoard[ch65288]Slave) from eBay, so that I could send/receive data from my Arduino using bluetooth.
When connecting 5V and GND, the led on the board starts flashing, I can find the device from my PC and pair with it, so it looks like the unit is working.
The manual also describes how you can configure the module so that it shows a different name and how you can change the baud rate (which defaults to 9600)
By connecting TX of the module to TX on the Arduino, and RX of the module to RX on the Arduino, I think I should be able to communicate to the module with the PC over USB.
When I open up ZTerm and connect to it, and enter the command 'AT', the unit does indeed respond with 'OK'.
My problem is that I can't get any of the other commands to work though, and the manual isn't very clear how to send them exactly.
(For example, do they actually mean a '+' character between AT and BAUD, or a return or space maybe, and it also doesn't say how to end the command. Sending AT didn't require a return to be send, but it doesn't say what it expects after the other commands)
Anyway, using various combinations of +, space, carriage returns and line feeds, I am still unable to get the module to respond to anything else.
Does anyone else have such a module and succeeded in configuring it?
did you notice the picture shows TX on MCU is connected to RX on blutooth module, and RX connected to TX.
Yes of course, but I think that is only correct when you want the bluetooth module to send communication to the MCU. (Which would be the case for regular use)
In this case however, I need to talk directly to the bluetooth module through the ftdi chip.
From the ftdi chip's point of view, rx and tx are swapped.
I think I'm correct in my reasoning here, since I do get a reply for the 'AT' command. I don't get any reply if I connect them the other way around.
I'm sorry I don't understand what do you exactly mean by connecting it "through the ftdi chip"? FTDI converts USART (MCU voltage level) to differential signaling and USB protocol. If you are connecting your bluetooth to the arduino and you want to communicat with the bootloader and program MCU over bluetooth, then needs to be connected, INSTEAD of FTDI chip, to RX and TX on MCU. As far as I know there is only one TX and RX on FTDI which is connected to the AVR.
I guess I'm not correctly understanding "I think I should be able to communicate to the module with the PC over USB" either. So your PC has bluetooth and you are pairing it with this slave bluetooth module? How does USB play a role here?
Can you please post a picture of your setup. I helps some one like me (not so smart) to understand your project better.
I got it working now using the Serial Monitor included with the Arduino IDE.
I think ZTerm probably didn't send a return as \r\n
I'll try to make more clear what I wanted to do:
-In my final project, I want to control the Arduino using my PC over Bluetooth.
In this case you of course need to connect RX from the bluetooth module to TX of the microprocessor, and TX from bluetooth to RX on microcontroller.
-The bluetooth module is configured with a default name, and a baud rate of 9600 bps.
For my project, I want the bluetooth device to have the name of my project, so that it is easier to find, and I also need it to send data at 38400 baud.
The bluetooth module can be configured manually, and to do this, you have to connect it serially before it is paired over bluetooth, and send some specific commands. (These are described in the datasheet that you can find on the ebay page)
Since the Arduino board already includes an USB->Serial chip (the ftdi), it was easiest to use this to program the bluetooth board, since I don't have a serial port on my laptop.
While doing this, the microcontroller doesn't play any role (and can even be removed from the board, but it doesn't really matter as long as it doesn't interfere with the commands it receives)
glad it's working now.
How did you find out about this board?
I've been looking into useful boards made in Taiwan or China, to import and sell in the U.S.
I know many stores sell electronics on ebay but most of them don't work-even with many positive reviews- (and I know many people don't want to risk getting stuff on ebay and not knowing if it would work or not). I've bought many samples to try and see if they work and have high quality, enough to sell here, but most of the times I'm disappointed. Even something as simple as a folding keyboard; some work some don't.
Do you thing this board is useful for others as well?
Just found it on ebay looking for a bluetooth module that would be cheaper than the original Arduino BT shield.
I didn't have much time to test it further, but have been able to test it a little today.
On my Macbook the device is working perfectly. I can communicate with the Arduino over Bluetooth in the same way as I can when it is connected to the PC. (Except for programming, since that requires some additional pins other than TX and RX to be connected I believe?)
On my Dell laptop I succeeded in seeing the device, adding it, but trying to connect to the created serial port using the arduino ide appears to fail. (Either the ide doesn't show the port, or when it does it hangs when trying to use the serial monitor)
I have had difficulties with other bluetooth devices too though, so the problem might be related to this laptop, I'll have to try with other pc's to be sure.
If it works on PC too, then it's definitely an interesting item.