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I have the evaluation kit EK-WT12 for Bluegiga WT12 module being controlled by a TI Launchpad. I have used the evaluation kit to communicate to a computer with SPP profile and I have sent and received data between RS232 input of the board and the PC connected via Bluetooth.

I have also used the TI Launchpad to communicate via RS232 to a computer for my desired functions. Works well. I am using a MAX232 circuit in order to convert its UART ports to RS232.

My problem is that, when I connect this microcontroller's UART ports through MAX232 circuit to the RS232 pins of EK-WT12, I see no data received in the data mode. I am not using flow control, so as told in the data sheet I grounded CTS and kept RTS floating. I connect only the GND, Rx and Tx pins to the output of MAX232.

Any ideas as to what may be causing the problem.

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Maybe check the baud rate. The default is 115200. Then check the MCU serial port is set to 8 data bits and one stop bit. The WT12 module should respond to a SET command. Check both sides are self powered is using RS232 since RS232 does have a power line.

Best way is to put an oscilloscope on the TX and RX data. And CTS , RTS lines are not needed.

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  • \$\begingroup\$ I am confident about the baud rates, and also I think when the baud rate is false, you still get something but in a distorted way. \$\endgroup\$ – natsirun Jun 11 '14 at 11:44
  • \$\begingroup\$ Hmm, how can I supply the power if they are not powering the RS232 line? \$\endgroup\$ – natsirun Jun 11 '14 at 11:47
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The WT-12 requires that the Tx/Rx pins be cross-connected, like a null modem, that is Rx of the WT-12 is connected to Tx of the MCU, and Tx of the WT-12 is connected to Rx of the MCU. So make sure that is the case.

Since you are using the evaluation board, this means pin 3 (Tx) of the DB-9 connector on the evaluation board is connected to pin 13 of the MAX232 chip, and pin 2 (Rx) of the DB-9 is connected to 14 of the MAX232.

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I think,you should control whether your microcontroller sends data or not before connection is established.Using pio5 pin you can understand it is connected and then you can start to send or receive data.Otherwise,in my opinion wt12 can not communicate because of the fact that it is busy due to data coming its data pins.

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