Car Plate Recognition System with Raspberry Pi and Node-RED

#1

Hi, I am trying to get a "Car Plate Recognition System with Raspberry Pi and Node-RED" ( https://randomnerdtutorials.com/car-plate-recognition-system-with-raspberry-pi-and-node-red/#comment-335263 ) running but keep getting an error message - error 26 on the cURL POST module when a take a picture.

Does anyone know what error 26 means and suggest a possible solution.

Thanks

Peter

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#2

Have you Googled the error?

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#3

Yes tried that with no success.

Peter

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#4

Wait, you googled 'curl post err 26' and didn't get any hits? Are you using a different google than I am?

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#5

https://www.google.co.uk/search?q=curl+error+26

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#6

Hi Peter,

Not really an answer to your 26 error, but since you want to have license plate recognition using the OpenAlpr cloud solution you might try my node-red-contrib-openalpr-cloud node...

Must admit that it has been a long time ago that I developed that node - when I was young, pretty and adored by all woman on this planet :heart_eyes: - so perhaps it is not up to date anymore. But be my guest!

Good luck with it !
Bart

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#7

Hi Bart, Thanks for your reply. I have looked at your Git Hub repository and loaded it onto my Pi. However when I log onto my Node Red I do not see the flow. I know I have done something wrong but cant figure our what.

Here is what I did;

Loaded 2018-06-27-raspian-stretch-lite onto my pi
ran update and upgrade
ran bash <(curl -sL https://raw.githubusercontent.com/node-red/raspian-dep-package/master/resources/update-nodejs-andnodered)
Then made a directory called Node-Red and changed to this directory
The ran npm install node-red-contrib-openalpr-cloud
Then ran cd to home and ran sudo systemctl enable nodered.service
then sudo reboot

Any suggestions gratefully received.

Peter

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#8

Wrong directory. When you run node-red for the first time it will make a folder .node-red (with a leading dot and no capitals). You can install the node in that folder then restart node red, or you should be able to install it using Mange Pallet in the node red editor.

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#9

Thanks Colin,

I have followed your advise, but still cannot see the flow in my node red.

Peter

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#10

Looking in the "flows" directory, there are no flows, the directory is empty

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#11

What do you see in the node red log when you start node-red? To see that, in a terminal run

node-red-stop
node-red-start

You can copy out of the terminal using Ctrl-Shift-C
When you past it here put a line containing three backtick characters before it and another such line after it, that will stop the forum from messing with the layout.

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#12

unfortunately, when I try to past the output I get - Sorry, new users can only put 2 links in a post.

Peter

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#13

Start a new thread and paste it there.

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#14

Ok, I have made some progress. However two nodes are causing a problem - * base64

  • jsonpath with the error message - Flows stopped due to missing node types.

Scratching of head continues.

Peter

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#15

Look at the information that node-RED prints to the log on startup.

That should identify the nodes you are missing

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#16

Ok so now the nodes are installed but the following error messages are being produced

msg.payload : buffer[66864]
[ 255, 216, 255, 224, 0, 16, 74, 70, 73, 70 … ]

Peter

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#17

What makes you think that is an error message?

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#18

Why not help yourself,
You might come faster to the solution if you publish your flow so that other members can analyze what you have done so far

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#19

Hi peter,

Looks like you have finally received a valid jpeg image buffer.
If you see at this link you will see what I mean. Summarized this is how the different image types start:

    var bmp = Encoding.ASCII.GetBytes("BM");     // BMP
    var gif = Encoding.ASCII.GetBytes("GIF");    // GIF
    var png = new byte[] { 137, 80, 78, 71 };    // PNG
    var tiff = new byte[] { 73, 73, 42 };         // TIFF
    var tiff2 = new byte[] { 77, 77, 42 };         // TIFF
    var jpeg = new byte[] { 255, 216, 255, 224 }; // jpeg
    var jpeg2 = new byte[] { 255, 216, 255, 225 }; // jpeg canon

So with a little luck you are almost there :wink:
Bart

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#20

P.S. You can also try the node-red-contrib-image-info node to get information about the image.

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