# Serial port /dev/ttyUSB0 closed unexpectedly

**URL:** <https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549>\
**Category:** General\
**Created:** [18 January 2020 23:02 UTC](https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549 "2020-01-18T23:02:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [18 January 2020 23:02 UTC](https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549/1 "2020-01-18T23:02:45Z")

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Today I have update my NR on my pi3B+ from 0.20.7 to 1.0.3.  
At the same time I have update some nodes among which the serial port node from version unknown to 0.10.0.  
Since that moment my comport is giving an error in the debug window `serial port /dev/ttyUSB0 closed unexpectedly`  
I removed the node and reinstalled it, but still not working.  
Any suggestion what could be the problem or can I install an older version of the serial port node?

Opening the port on the command line with `minicom -b 115200 -o -D /dev/ttyUSB0` will show me the data from my smart meter, so it doesn't look like a hw or os problem

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**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 January 2020 01:26 UTC](https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549/2 "2020-01-19T01:26:07Z")

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Couple of things I would check:  
1 - USB connector is firm when you plug it in.  
2 - Power supply.

Although if you can open it from a terminal, it may be something else.  
But, as I have often found, don't discount the obvious. They sometimes bite you hard if you ignore them long enough.

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**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [19 January 2020 10:57 UTC](https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549/3 "2020-01-19T10:57:50Z")

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Installed the previous version of serialport 0.8.3 with `sudo npm install -g --unsafe-perm node-red-node-serialport@0.8.3` and it looks that everything works again.  
I will open a issue on github to report the problem.

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**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 January 2020 11:05 UTC](https://discourse.nodered.org/t/serial-port-dev-ttyusb0-closed-unexpectedly/20549/4 "2020-01-19T11:05:40Z")

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Good to hear.