USB serial on Raspberry Pi

[RGV250]

Hi,
The first character of the string will be '0', but this is 0x30 (or 48 decimal) not 0. Have a look at an ASCII table.
It is getting embarrasing, i should have (did) know that but I think with all the trouble getting this to work I am not thinking well.

I am stumped now, I found a comment in the RPI_CAL_UART file regards removing the console from cmdline.txt. and adding enable_uart=1. I aloso found somewhere that mentions disabling bluetooth as that uses the port.
I have done all that but still nothing.

I have added a test for data in the first element of the string and nothing, also the length of the incoming string is 0.

This is the info on the pi showing the device is attached to ttyusb0.

Pi info.jpg (66.56 KiB) Viewed 2802 times

Is there a way I can confirm the symlink is correct?

Bob

[RGV250]

Hi,
After going over loads of it again and again I finally have it working, I really would like to know what I did in case I need to do it again.
Tomorrow I will connect the CT's to the cables to see if I get live data.

Thanks again for you help Leigh.

Regards,
Bob

[LeighM]

Brain confusion - yes happens to all of us - far too often

Now that we have numerous serial channels in the UART component,
choose one above the existing devices and avoid the need to do any disabling of them, console, etc.

Glad to hear you now have progress.

[RGV250]

Hi,
A bit short lived, I moved it to where it needs to be for the current transformers and now no data. I tried to do everything again but nothing.

Are you saying to use serial 3 or 4?, do I need to redirect the symlink?

Bob

[LeighM]

Yes, and yes

[RGV250]

Hi,
Really getting annoyed with this now, it is now not a flowcode issue but hopefully it can be resolved to help others if they have the same issue later.

I changed to serial4 and it works, reboot the pi and it does not and when I check the liknk is no longer there.
I found this command ls -l /dev which shows the link for serial4.

serial4.jpg (40.41 KiB) Viewed 2775 times

What I need to find out now is how to make the symlink non volatile, I wonder if it can be placed in the config.txt file?

Bob

[RGV250]

Hi,
Adding the symlink ln -s /dev/ttyUSB0 /dev/serial4 (in my case) to /etc/rc.local appears to work.

Bob