Hello @lindachang0407 ,
See below, please!
================================================================
1. Connections with Bluetooth UART
iMX93 side 88Q9098 side
GPIO_IO14(LPUART3_TX)(Ouput)------------------->BT_UART_RX
GPIO_IO15(LPUART3_RX)(Input)<-------------------BT_UART_TX
GPIO_IO16(LPUART3_CTS_B)(Input)<--------------BT_UART_RTS
GPIO_IO17(LPUART3_RTS_B)(Ouput)------------->BT_UART_CTS
Pay attention to I/O directions when connecting to i.MX93 LPUART3 pins, which is very important!
2. IO level (Using 3.3V IO)
NVCC_GPIO = 3.3V, so on 88Q9098 side, VIO should also be set to 3.3V (ublox EVK, VIO is controled by J102)
3. IOMUX in i.mx93 device tree
In default device tree, LPUART5 is used for Bluetooth, so we should change code like below, you can change LPUART5 to LPUART3.
--imx93-11x11-evk.dts
......
pinctrl_uart3: uart3grp {
fsl,pins = <
MX93_PAD_GPIO_IO14__LPUART3_TX 0x31e
MX93_PAD_GPIO_IO15__LPUART3_RX 0x31e
MX93_PAD_GPIO_IO17__LPUART4_RTS_B 0x31e
MX93_PAD_GPIO_IO16__LPUART3_CTS_B 0x31e
>;
};
......
Then change UART5 node to be UART3
&lpuart3 {
/* BT */
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3>;
status = "okay";
bluetooth {
compatible = "nxp,88w8987-bt";
};
};
================================================================
Try it, please!
Thanks!
Regards,
weidong
