I’ve just purchased two Bluetooth modules from Sparkfun, but I can’t get either to work!? I purchased the Bluetooth v1.2 DIP module (RF-BT) and the Serial Miniature Bluetooth RF Link Base/Remote pair (RF-BlueSMiRF).
I currently have the DIP module on a breadboard powered by a 3.3V supply. When I power the module up, it draws about 48mA.
So, I stuck in the USB BT Dongle into my computer, and WinXP found the device and configured it as expected. Using WinXP’s built in Bluetooth Manager, I did a device search, found the “BlueRadios” module and paired with it using the “default” passkey. Windows then configured two COM ports to use with the module (Incoming and Outgoing).
Ok, so everything is going as expected so far. Now I open up Hyperterminal and connect to the Outgoing COM port. A connection is established (current draw drops to about 22mA), and I proceed to enter +++ ENTER. Nothing happens!? The first thing I noticed is that Hyperterminal never gave me an option to set the baud rate, etc. So I disconnect, and goto the connection properties to set the baud rate, but it wont let me. When a connection is made, I see “Auto-detect” down the bottom in Hyperterminal.
The other thing I noticed is that when I type in the Hyperterminal, the current draw increases to around 28mA (indicating to me that the module is receiving something).
I’ve also scoped the TX pin on the module, but there’s nothing coming out when I type.
So, what I think is happening is that Hyperterminal is sending the data at the wrong baud rate, but it wont let me set the correct baud rate!?
I’ve tried the exact same setup with the BlueSMiRF, but it behaves in the exact same way :?
Have you tried using a regular RS-232 serial connection to connect to the hardware side of the BlueTooth module? I’ve found that that sometimes helps you to see what’s going on, if connections are being made etc. It’ll also give you another way to see if the module is recieving commands. I’ve been playing with the Bluetooth v1.2 DIP module’s and all you have to do to wire up the hardware side is put a MAX3222 (or something like it) between your serial cable and the BlueStamp.
If your worried that Hyperterminal is giving you some grief you might want to try a different terminal program. I’ve found that DockLight seems to be fairly good and easy to use. You can get a fairly functional evaluation version at http://www.docklight.de/
I tied the RX/TX lines together (forming a loopback), and now Hyperterminal receives valid data when I connect to the BlueSmirf. I also noticed that Hyperterminal configures itself at 2400bps baud.
So, it seems like before you can send the BT modules a command (or anything for that matter), the module needs to send you something first. Seems a little odd…
Anyway, now I have another problem, I am trying to make a Bluetooth Accelerometer, by simply connecting the SerAccel v3 to the BlueSmirf. However, all i’m getting in Hyperterminal is invalid data (most likly caused by a baud rate mismatch).
I’ve tried entering config mode in the BlueSmirf to set it’s baud to 115200 (the same as the SerAccel v3), but still no good :?
I then hooked up the BlueSmirf to the UART on my AVR Dev board (STK500) and programmed the AVR to output some data at 9600 to the BlueSmirf, this worked ok. I saw the data in Hyperterminal fine. So, this makes me think that the BlueSmirf can’t handle the 115200 baud of the SerAccel v3??
So…what I would like todo is reprogramm the SerAccel v3 to output at 9600bps baud. Do anyone know how I would go about this?