LCD20x4-I2C raspbian bullseye 11

General
1

Hello All, I updated my Pi 0 W to buster and I cant get this node to work. The flow and node worked in the with the older versions or raspberian so my function block code should be fine. As a test to make sure the LCD and I2C is working properly I ran a python script and the display worked correctly.

Is anyone using LCD20x4-I2C or another node with Bullseye 11 with success? I am a "barely" intermediate user of node red and pi's. so any help would be greatly appreciated.! Thanks all

PRETTY_NAME="Raspbian GNU/Linux 11 (bullseye)"
NAME="Raspbian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
2

Hi Guys, Is anyone using LCD over I2C with latest version of raspberian and Node Red?

3

I see you open an issue on github.

Did you check this is not your problem -
Node not working on LCD20x4-I2C

4

Yes i did check it. To the best of my understanding with the way the code works. It is not defaulted to 0x3C in there. I have selected 0x27 and verified it correct by using the I2C detect command in the terminal. Additionally, this worked before i upgraded Raspberian and node red. So the wiring and node red code i made should be fine..

To be honest I am not sure what I should be doing to get proper help on something like this. Is what I did correct in opening an issue on GitHub and asking the question here? Any guidance I would really appreciate as I learn more about this world.

On another note. I rolled back node red to 2.0 and I also cant get it to work. So I dont think it is a node red issue per say.. Maybe it is on the OS side?

Code from git hub regarding the address below.

 if (n.address !== undefined){
            this.address = n.address;
        }
        else{
            this.address = "0x27";
5

Is there a way I can use Node Red to Debug this a bit and give more information to the group?

6

As you said that it works OK from the command line then it's most likely a problem with the LCD20x4-I2C node, or dependencies. How did you upgrade, is it a fresh install, if so did you install this - sudo apt-get install python-smbus ?

It hasn’t been updated for 2 years so may not be compatible with latest OS. You are right to open an issue on GitHub as its not really a node red problem.

Unfortunately the author of the node hasn't responded to any of the other issues in that time either, so you may be out of luck.

7

You could provide some more info on what happens when you try to use it, do you see anything in the debug pane on the right, or in the node-red logs ?

8

Well with the help of a friend, I believe it is a problem that the LCD20x4-I2C node requires Python2 which i guess is not supported in Bullseye OS? I rolled it back to Buster and the latest version of Node Red and its working.

So i guess this node is dead in the water moving forward :frowning:

9

@smcgann99 Thank you for replying and offering your time to assist me. I am surprised more people are not using I2C LCDs in Bullseye. I suppose this will become more of an issue in the future. Hopefully someone can fork the repo for Python3 someday.

1 Like
10

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