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Bluetooth uart and DTE mode

Question asked by Jerome Depotter on Mar 4, 2016
Latest reply on Mar 7, 2016 by jimmychan


I'm trying to use imx6 qdl uart for bluetooth. My bluetooth chip is BCM4339.

I want to use RTS CTS flow control in DTE mode. In DCE mode, it was working without flow control but flow control was not working. So I try DTE mode and this time Rts Cts seems to work but not Rx and Tx.

 

So here are my connection :

 

pinctrl_uart2_3: uart2grp-3 { /* Bluetooth mode */

  fsl,pins = <

  MX6QDL_PAD_SD3_DAT5__UART2_TX_DATA IPAD_CTL_PWUART           (connected to Rx BCM4339)

  MX6QDL_PAD_SD3_DAT4__UART2_RX_DATA IPAD_CTL_PWUART           (connected to Tx BCM4339)

        MX6QDL_PAD_SD3_CLK__UART2_CTS_B    IPAD_CTL_PWUART         (connected to CTS BCM4339)

  MX6QDL_PAD_SD3_CMD__UART2_RTS_B    IPAD_CTL_PWUART              (connected to RTS BCM4339)

  >;

  };

 

When I try to enable bluetooth, HCI reset frame is sent on Tx pin of BCM4339. So I try to invert Rx and Tx with imx6 mux. But the HCI reset frame is still sent to Tx pin of BCM4339.

 

How should I configure Rts, Cts, Rx and Tx to make this work in DTE mode ?

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