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STM32F4 Discovery UART problem using Rn-41 Bluetooth module

Question asked by icecoldies on Mar 21, 2013
Latest reply on Dec 25, 2014 by p.avinash.001
I have the STM32F4 communicating with hyperterminal on windows 7 using a serial cable. My discovery board is plugged into an Embest expansion board which breaks out to an RS232 serial port and at the PC end I have a usb to serial converter as I have no serial port. I have gone back to the UART example Embest provide in their examples folder for the expansion board. All works fine hyperterminal receives the printf data.

I want to replace the serial cable with a Roving networks Rn-41-ms bluetooth device. I have fitted the Rn-41 to my board with a 3V supply and ground and I can talk to it via hyperterminal fine i.e can use get/set comands to confirm change settings on the device. I am using a bluetooth dongle at PC end.

My problem comes when trying to transmit from my program via the bluetooth device to hyperterminal. In the UART example COM1 is used for UART6 which is the serial port on the expansion board, so I have selected COM3 for UART1 which is shown STM32F4_discovery.h file. The way I have changed to COM3 is by basically changing all the COM1's in the main.c to COM3 but I've also enabled hardware flow control as this is required for the RN-41 device. The program compiles and downloads fine but no data is recieved by hyperterminal when run on the ST board?

I have set board rate, parity, stop bits etc the same on ST program, Rn-41 bluetooth device, PC bluetooth dongle and hyperterminal.

Any ideas or advice on other settings I should consider when changing com ports or debugging methods for UART appreciated, I don't have use of an oscilloscope until monday.

Expansion board
http://www.embest-tech.com/shop/product/dm-stf4bb-base-board.html

Bluetooth module
http://uk.farnell.com/jsp/displayProduct.jsp?sku=2144010&CMP=e-2072-00001000&gross_price=true&mckv=YKMwxwd8|pcrid|14164337469|plid|{placement}

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