# Serialport issue

**URL:** <https://discourse.nodered.org/t/serialport-issue/15980>\
**Category:** General\
**Created:** [27 September 2019 08:00 UTC](https://discourse.nodered.org/t/serialport-issue/15980 "2019-09-27T08:00:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ndex11](https://avatars.discourse-cdn.com/v4/letter/n/c57346/32.png) [@ndex11](https://discourse.nodered.org/u/ndex11)\
**Post date:** [27 September 2019 08:00 UTC](https://discourse.nodered.org/t/serialport-issue/15980/1 "2019-09-27T08:00:15Z")

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Hi, I am trying to read data from serial port with no luck. I am using USB/Serial converter with pl2303 and I shorted RX TX pins so I can write data to the serial port from nodered and then read them from Linux console with cat -v \< /dev/ttyUSB0, I can also send data from console by echo "aaaa" \> /dev/ttyUSB0 and then read them with cat command, but I can NOT read any data in nodered.

I have one Serial Output node which is triggered with Inject node and on push is sending timestamp and I have also one Serial Input node which is connected to the debug node. Both of them have status connected. But there are no data in debug node when I press inject. I can see that timestamp was send by cat /dev/ttyUSB0.

I think that problem has to be in Nodered because serial link is working. Do you have any idea what to do or where are any relevant logs stored which I can use to determine what is going on in nodered?

My setup:  
Raspberry pi 3b+  
Dietpi - latest  
Nodered -latest  
Nodered is running with root privileges  
USB/Serial converter - Prolific pl2303

Thank you for any suggestions

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [27 September 2019 08:06 UTC](https://discourse.nodered.org/t/serialport-issue/15980/2 "2019-09-27T08:06:17Z")

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I assume that you've tried the obvious such as checking that the user running NR is in the wheel group or whatever DietPi uses? Also that you have tried a console based serial terminal to make sure you are using the correct serial settings in the serial-in node?

Also, are there any errors reported in the NR log?

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<div class="post-metadata">

**Author:** ![ndex11](https://avatars.discourse-cdn.com/v4/letter/n/c57346/32.png) [@ndex11](https://discourse.nodered.org/u/ndex11)\
**Post date:** [27 September 2019 08:15 UTC](https://discourse.nodered.org/t/serialport-issue/15980/3 "2019-09-27T08:15:54Z")

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NodeRed is running under the root user so I think there is no need to be in any group. I tested serial link only in unix console by cat and echo commands of /dev/ttyUSB0. I thought, if I set up serial nodes with some settings and then deploy, It will open port with that settings (baud rate etc.) and If i shorted the rx with tx pins of converter it should have correct settings for communication Am I right?  
I dont know if there is any NR log /error log, I can read only that log which is in console when I run node-red in console. There are no errors in console log.