svrsig
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Re: Serial port

Tue Mar 06, 2012 9:09 am

The development RPI boards could be connected to a terminal using a serial port (useful to do debugging when getting RISC OS to work). Will the production boards have headers or exposed pins that serial port wires can be soldered to? Will it matter whether lead free or non-lead free solder is used (I only have the proper solder not this new lead free stuff)? Presumably it would be better to solder a connector rather than individual wires. If the headers are not present will the solder holes be open or do we need to drill them out to fit the connector?

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rurwin
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Re: Serial port

Tue Mar 06, 2012 9:22 am

Do not drill out anything, you would wreak it.

The serial port signals are available on the GPIO connector at 3.3V logic levels. An RS232 convertor would be required to connect to a standard serial port.

The connector is almost certainly not fitted. The beta boards had the holes of non-fitted connectors clear of solder. Nobody has yet seen a production board, which have been made by a different company.

If the holes are blocked then we will all moan, but they can be cleared by careful and repeated application of a solder pump. NOT a drill.

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psergiu
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Re: Serial port

Tue Mar 06, 2012 10:11 am

Instead of a RS232 converter you can use a USB-Serial phone cable - like the Nokia DKU-5 (or a clone) - cut the Nokia connector and find out with a multimeter what each wire is for:

Pin# - Use

======

4 -  3.3V
6 -  RX
7 -  TX
8 -  GND


svrsig
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Re: Serial port

Tue Mar 06, 2012 11:04 am

I should have said carefully drill out the solder (which is quite soft as it has lead in it) and not the pads. Which pins of the GPIO header are the serial port please? I seem to remember you need RX TX CTS RTS and GND.

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TheCrazyInventor
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Re: Serial port

Tue Mar 06, 2012 11:26 am

You only need RX, TX and gnd for basic communication between 2 devices. If you want to do all kinds of fancy handshaking in your software, then you need CTS and RTS as well.

Be VERY careful when drilling out pads. If your drill is too large or not sharp enough, you may rip the whole trace that is attached to that pad, off the board. I doubt the holes are filled with solder, but if they are, I'd just use some desoldering braid. If you have access to a vacuum solder sucker, definitely use that.
"Anything that can possibly go wrong, does" -M

geeday
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Re: Serial port

Tue Mar 06, 2012 11:44 am

svrsig said:


I should have said carefully drill out the solder (which is quite soft as it has lead in it) and not the pads. Which pins of the GPIO header are the serial port please? I seem to remember you need RX TX CTS RTS and GND.


I think the answers to your question are: google, search and FAQ. However, I will save you some time and give you this:

http://elinux.org/RPi_Low-leve.....eripherals

(I'm only saying what the admins are thinking)

bredman
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Re: Serial port

Tue Mar 06, 2012 12:59 pm

It is a really bad idea to drill out solder. Spend $4 dollars and get yourself a solder sucker, for example dx.com/p/13418

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