Luckfox Forums

Hello,

I have a Luckfox Pico MAX. Serial communication works on all UARTs, when using only RX and TX pins, and no flow control.

UART0, UART1, and UART4 have available RTS and CTS pins, and I tried to use hardware flow control with them; however, without success.

In sysdrv/source/kernel/arch/arm/boot/dts/rv1106.dtsi RTS/CTS pins are already enabled for UART1:

pinctrl-0 = <&uart1m0_xfer &uart1m0_ctsn &uart1m0_rtsn>;

I did the same for UART0 and UART4.

Unfortunately, this did not help - hardware flow control did not work with any of them. I also tried to explicitly disable i2c and sdmmc pins in the device tree (in case their function overlaps with rts/cts), but again without success.

I would be grateful if somebody could help me on this issue - how to enable RTS/CTS function on UART0, UART1, or UART4.

Hello, in the file $SDK/sysdrv/source/kernel/arch/arm/boot/dts/rv1106g-luckfox-pico-ultra-w.dts, there is a configuration that uses UART0 flow control to control the wireless module.
It is recommended to use the iomux command during testing to determine if the reassignment of relevant pins is correct. The startup of flow control generally only requires configuring the pinctrl properly.

Thank you! It works when I put rts and cts pins into correct bank using iomux command. Now I will try to find why
pinctrl in the device tree isn't working as expected. Hopefully, the example with wireless module control will help me.