Talk:Raspberry Pi Serial Ports

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Its worth adding a dire warning about the Pi having 3.3v serial ports. That's not compatible with PCs at all. Its not compatible with some USB to serial devices either. Getting it wrong will destroy the serial port on the Pi.

--NeddySeagoon (talk) 18:25, 15 August 2017 (UTC)


--Jon Wilder (talk) 14:34, 15 August 2017 (PDT)

Modify The Boot Files. The page is written to perform this step on the Pi. While you can do that if it works first time, if you mess up, you can't recover that way.

I suggest moving the SD card to a PC for this. That way, readers can have as many goes as they need and you have it covered.

--NeddySeagoon (talk) 18:53, 15 August 2017 (UTC)

If you mess this up that bad, you should probably stay on Raspbian. Just sayin'. ;)

--Jon Wilder (talk) 14:20, 15 August 2017 (PDT)

How do you test if it works, or is actually getting the serial link to work out of scope of this page?

It may be worth explaining a little about baud rates, start bits, stop bits and parity, so that readers are informed what the numbers mean.

You did set the baud rate, console=ttyS0,115200, the same on the console command line and in inittab and left the no parity, one stop bit for the defaults. I've set it differently. Just the once.

--NeddySeagoon (talk) 18:53, 15 August 2017 (UTC)

Getting the serial link to work is out of the scope of this page. However, most programs written to use the serial port have some sort of serial library available that handles all of the low level serial stuff in the background, such as setting the baud rate, frame format, parity, etc.

Theoretically, after this configuration, anything that worked with the serial ports under Raspbian Jessie should work under Gentoo.

One Python application I'm writing to work with Synapse Wireless LR-WPAN radios uses Python libraries from Synapse wireless that handle the low level serial link stuff while all I have to do in software is specify the correct serial port for the link.

If there is interest to learn the low level stuff, I have quite a bit of UART experience so I can generate a separate article for that. This page was created for those who have apps that worked with the serial ports under Raspbian but can't seem to get them to work under Gentoo.

--Jon Wilder (talk) 14:20, 15 August 2017 (PDT)

On the testing front, consider setting up a serial terminal (not the console) to get the serial link working first, then moving the console to the known working serial link.

Build on what you know works.

--NeddySeagoon (talk) 18:53, 15 August 2017 (UTC)

No comments on the udev parts. I run an Old_Fashioned_Gentoo_Install so I don't have anything like udev.

--NeddySeagoon (talk) 18:53, 15 August 2017 (UTC)

Well done. Looks good to me.

--NeddySeagoon (talk) 18:53, 15 August 2017 (UTC)