Hi,
Following the link you suggested I modified overlay dts i.e. uart3-pi5-overlay.dts
This has brough my DTS node to to show "RS485 is enabled at boot time" at initial level,
In config.txt, I used this settings->you may see following node definition-Should I consider this as RS485 is enabled initially?
Following the link you suggested I modified overlay dts i.e. uart3-pi5-overlay.dts
Code:
/dts-v1/;/plugin/;/{compatible = "brcm,bcm2712";fragment@0 {target = <&uart3>;frag0: __overlay__ {status = "okay";pinctrl-0 = <&uart3_pins>;};};rs485: fragment@1 {target = <&uart3>;__dormant__ {linux,rs485-enabled-at-boot-time;rs485-rts-delay = <0 0>;rs485-rts-active-low;};};__overrides__ {ctsrts = <&frag0>,"pinctrl-0:4=",<&uart3_ctsrts_pins>;rs485 = <0>,"=1=2";rs485_invert_rts = <&rs485>,"rs485-rts-active-low";rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";};};In config.txt, I used this settings->
Code:
dtoverlay=uart3-pi5,ctsrts=on,rs485=on,rs485_invert_rts=ondtparam=uart3-pi5=onCode:
serial@3c000 { arm,primecell-periphid = <0x341011>; pinctrl-names = "default"; rs485-rts-active-low; pinctrl-0 = <0xc6 0xc7>; clock-names = "uartclk", "apb_pclk"; cts-event-workaround; interrupts = <0x2c 0x04>; clocks = <0x02 0x0f 0x02 0x06>; skip-init; linux,rs485-enabled-at-boot-time; uart-has-rtscts; rs485-rts-delay = <0x00 0x00>; compatible = "arm,pl011-axi"; status = "okay"; reg = <0xc0 0x4003c000 0x00 0x100>; phandle = <0xa9>; };Statistics: Posted by shailesh170 — Thu Dec 18, 2025 5:49 am