UART connection's Rx error when BT enabled

Question

Hi,

I have been using an UART connection for serial communication but it stops working when I enable the Bluetooth module and initialize it. The error I receive is the same as if I connected the UART's Rx pin to GND.

UART overlay definition, also tried using the uart2 but it also fails.

&uart1 {
    status = "okay";
    tx-pin = <34>;   //For pins P1.0 through P1.31, add 32 to the pin number.
    rx-pin = <33>;   //For pins P1.0 through P1.31, add 32 to the pin number.
};

Bluetooth configuration

CONFIG_BT=y
CONFIG_BT_SMP=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_ATT_PREPARE_COUNT=5
CONFIG_BT_SETTINGS=y
CONFIG_BT_PRIVACY=y
CONFIG_BT_DIS=y
CONFIG_BT_BAS=y

UART Error Messages

<err> : UART rx stopped, reason: 4
<err> : UART rx stopped, reason: 8

I even tried connecting directly the power source pin to the RX pin but it still fails.

Erasmo · Accepted Answer

Hi,

I changed the pins

&uart1 {
	status = "okay";
	tx-pin = <36>;
	rx-pin = <37>;
};

and the UART connection stays active.

The problem was that the pin was used by the Network core when the Bluetooth is active.

Thanks for the help.

regards

Erasmo