Adding a USB serial port, getting started

Hi all.
I would like to use the RS232 nodes on Node Red (to control a projector).

I am a PC user, and when I add an USB>RS232 adaptor, Windows scoots off and finds the drivers. So, being new to the Pi, does it need drivers, does the RS232 libraries contain generic drivers, what do I need to do ? I have a popular USB>232 dongle ( I use for work, keen to test with this first.

Any simple guidance much appreciated :slightly_smiling_face:

The manual for your projector (or "beamer" for out German friends) should say what its connection parameters are.

Typically you will install a driver for your usb dongle and again, the manual should tell you. However, if you plug it in and you get two serial ports pop up, you are good to go. You can check that the ports are active and have the correct drivers by looking in Control Panel's "devices".

If the 2 ports are there, you should be able to use them directly. You will need to know the connection parameters for the projector though. Once you have that, best to try to connect from a terminal tool first. PuTTY (or better KiTTY) or one of many other terminal tools will enable you to connect.

If that works, close the terminal and start up node-red, add the serial node and configure a connection with the same settings and you should be good to go.


Usually on a Pi (assuming running Raspbian) you shouldn't need drivers for a serial/usb adaptor. If you watch syslog and plug it in you will see if it connects. So in a terminal run
tail -f /var/log/syslog
which will start watching the log, then plug it in and see what happens. There will be a lot of blurb about usb devices but somewhere it should say that that the device has connected as ttyUSB0 (or something similar). That is what you need to put in the serial port node.

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He did say PC though. So most likely Windows.

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sorry @TotallyInformation - he said he already was PC user... "so being new to the Pi...." - so you've lost him to the dark side :wink:

typing lsusb at a command prompt should show if it has been recognised... and if that works then using a serialport node inside Node-RED should be able to find it if you click on the search icon (magnifying glass) in the add new serialport config panel,

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Ach, I hate it when you are right! Never mind. In that case I'll crawl back into a box - I might even get my Macbook Pro out to abuse as a cheese grater just for fun (if you get a chance feel the edges of a Macbook Pro, especially the gap behind the hinge when it is closed - Ouch!) :crazy_face:


Thanks guys, really helpful & much appreciated, lots of things to try !

Just to say guys, this all worked much easier than expected, I was expecting to have drivers hell and it was not. Node Red found the device right away ! Havent connected to the beamer yet, but ive got the protocols so should be easy.

Thanks all, womnderful forum :slight_smile:


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