# TX2-NX UART not work (JetPack4.5.1)

**URL:** <https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919>\
**Category:** Jetson TX2\
**Created:** [May 14, 2021, 6:21am UTC](https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919 "2021-05-14T06:21:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Luna2020](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/luna2020/32/12948_2.png) [@Luna2020](https://forums.developer.nvidia.com/u/Luna2020)\
**Post date:** [May 14, 2021, 6:21am UTC](https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919/1 "2021-05-14T06:21:51Z")

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Hi,

I’m using TX2-NX SOM and NX carrier board (customer designed), UART( PIN203/205) and UART(PIN99/101) can’t work, , if change to NX SOM.  
I tried short TX/RX (PIN203/205) and concect to Host PC both not work.

sudo minicom /dev/ttyTHS1

```auto
nvidia@tx2-nx:~$ ls /dev/ttyTH*
/dev/ttyTHS1 /dev/ttyTHS3

sudo minicom /dev/ttyTHS1 not work   
sudo minicom /dev/ttyTHS3 not work

```

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<div class="post-metadata">

**Author:** ![Luna2020](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/luna2020/32/12948_2.png) [@Luna2020](https://forums.developer.nvidia.com/u/Luna2020)\
**Post date:** [May 14, 2021, 6:51am UTC](https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919/2 "2021-05-14T06:51:58Z")

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Hi,

I refer to this topic UART-PIN203/205 works fine.

```auto
1. Enable THS2 with /Linux_for_Tegra/bootloader/tegra186-p3636-0001-p3509-0000-a01.dtb
+	serial@c280000 {
+ compatible = "nvidia,tegra186-hsuart";
+ status = "okay";
+	};

2. Disable bpmp-dtb port with /Linux_for_Tegra/bootloader/t186ref/tegra186-bpmp-p3636-0001-a00-00.dtb
-	serial {
- port = <3>;
- has_input;
-	};

3. commands
$dtc -I dtb -O dts bootloader/t186ref/tegra186-bpmp-p3636-0001-a00-00.dtb > new.dts
$ dtc -I dts -O dtb -o new.tegra186-bpmp-p3636-0001-a00-00.dtb new.dts
$sudo mv new.tegra186-bpmp-p3636-0001-a00-00.dtb bootloader/t186ref/tegra186-bpmp-p3636-0001-a00-00.dtb > new.dts

$sudo ./flash.sh -r -k bpmp-fw-dtb jetson-xavier-nx-devkit-tx2-nx mmcblk0p1
$sudo ./flash.sh -r -k kernel-dtb jetson-xavier-nx-devkit-tx2-nx mmcblk0p1

```

> [@TX2 NX RS232 Communication Problem](https://forums.developer.nvidia.com/t/tx2-nx-rs232-communication-problem/173226/7):
>
> we found this file in this path Linux\_for\_Tegra/bootloader/tegra186-bpmp-p3636-0001-a00-00.dtb we transformed .dtb file to .dts Removed this serial part - serial { - port = \<3\>; - has\_input; - }; Then what should we do now? Should we turn it to dtb, replace the original file (tegra186-bpmp-p3636-0001-a00-00.dtb) and re-flash it (sudo ./flash.sh -r -k kernel-dtb jetson-xavier-nx-devkit-tx2-nx mmcblk0p1)? Thanks

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<div class="post-metadata">

**Author:** ![kayccc](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/kayccc/32/14043_2.png) [@kayccc](https://forums.developer.nvidia.com/u/kayccc)\
**Post date:** [May 14, 2021, 7:21am UTC](https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919/3 "2021-05-14T07:21:41Z")

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Glad to know issue resolved, thanks for the update.

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<div class="post-metadata">

**Author:** ![nadeemm](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/nadeemm/32/367020_2.png) [@nadeemm](https://forums.developer.nvidia.com/u/nadeemm)\
**Post date:** [October 18, 2021, 6:14pm UTC](https://forums.developer.nvidia.com/t/tx2-nx-uart-not-work-jetpack4-5-1/177919/4 "2021-10-18T18:14:54Z")

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