Connecting Arduino to Pi 5 and Node Red

General
1

I'm very new to the Pi and Node Red and I've run into a perplexing problem with Node Red and an Arduino with Firmata installed. I'm always able to see the USB port in Terminal as /dev/ttyUSB0/ however I'm absolutely unable to get it to work in Node Red even for the Blink test. I have all of this working on a Win 11 install of Node Red and so after a couple of days of searching and finding no solution I figures I'd ask the experts.

Thanks in advance

2

I've now installed Node Red on another Win 11 PC and the Arduino In and Out Nodes don't work because no com port shows up for me to attach to. I have no idea how I got this to work on the first PC because the overall installation is not very intuitive. Example try to install the windows build tools module doesn't install because it's been deprecated. Are there newer instructions somewhere that don't have these issues.

3

Welcome to the forum @Technogeek.

What operating system do you have on your Pi?
How did you install Node-red?
Which Arduino board do you have?
Did you follow an on-line tutorial (link please) to setup Firmata and test it without Node-red, eg pyfirmata?
Can you show us your Node-red flow? A screen capture would at least give us an idea of which nodes you are using, an export even better (Export the flow and post it here using the </> button).
Have you tried different USB cables?

Node-red certainly can run perfectly well on Windows PCs but I've always found it an unwieldy combination. My preference is always to use a Pi.

4

Pi OS - Current version of Bookworm, 6.6, Debian 12, 64 Bit
Node Red installation - Running on Raspberry Pi : Node-RED
Arduino Nano, Firmata has been tested and works on my first Windows install.
Yes I have tried different cables.

What's odd is that I can connect to the com port through the 'Serial Out Node' on both the Pi and second Windows 11 install however no com port is available in the 'Arduino Out Node'. With the 'Serial Out Node' I do get a connection when I deploy the flow. On the Pi I need to create a com port and with Window s the Arduino shows up as com3.

Screenshot 2025-01-20 085808
Screenshot 2025-01-20 085808796×583 48.8 KB

5

What I wanted to find out was if you can access the Arduino from the Pi by other means than Node-red.

I hope that someone with knowledge of the Arduino nodes can help you.
I do sometimes use Arduino code but only on ESP devices, which have wifi so there's no need for serial connections.

6

The link is in the previous email.
Yes I can access the Arduino, I actually installed the Arduino IDE and I was able to upload code to it.

Thanks

7

The link in your previous post is to the Node-red installation instructions, which is not what I asked for.
It no longer matters though, I clearly can't help you, sorry.

8

So I got the Arduino with Firmata working on my Pi 5. I have no idea why its's working but it's working. I ran the flow in the pic above and all of the Arduino Output Nodes control the Digital Pins 2 to 9 properly, yet the Pin 3 to 9 Nodes always say "connecting" instead of "connected".

Thanks everyone for your help.