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Re: What have we missed?

Posted: Fri Nov 25, 2011 3:07 pm
by albertfrutos
I read in the Wiki (beginners) that we have to connect the board to the computer using COM (RS232). The problem is that I don't see a COM (RS232) connection in the board schematics. In the computer we can use a USB-to-RS232 adaptor, but in the board... (the wiki says the adaptor in the computer, not the board). How will we do this?

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:17 pm
by kme
The UART pins are the RS-232 connector (RX, TX and power only).

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:19 pm
by albertfrutos
So... will I have to weld a RS232 to the board?

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:47 pm
by kme
Did you ever use anything but power and RX/TX from your RS-232? The connector is mainly meant to be for board debugging and Linux console output.

Have you read this? http://elinux.org/RaspberryPiBoard#UART

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:49 pm
by albertfrutos
Thanks! I hadn't seen it. I hope more documentation will be provided when the device is launched, including how to connect the COM/RS232 to the board (welding, I suppose) and how to connect it to the computer. I think a full tutorial would be so useful for the newbies :)

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:52 pm
by Montekuri
Quote from albertfrutos on November 25, 2011, 15:07
I read in the Wiki (beginners) that we have to connect the board to the computer using COM (RS232). The problem is that I don't see a COM (RS232) connection in the board schematics. In the computer we can use a USB-to-RS232 adaptor, but in the board... (the wiki says the adaptor in the computer, not the board). How will we do this?
For what purpose do you want to connect the R-Pi device to a computer?
Maybe you can use USB to USB connection. Or by home network.

Re: What have we missed?

Posted: Fri Nov 25, 2011 3:53 pm
by johnbeetem
I haven't tried the product myself, but FTDI has USB to TTL UART cables which might work with the RasPi GPIO header depending on what signals are available on the GPIO. Web site price is between RasPi Model A and B.

http://www.ftdichip.com/Produc.....BMPSSE.htm

I don't know why they have separate products for MPSSE (SPI, I2C, or JTAG) and UART. I believe the FTDI chip can be configured for either. My guess is that the only difference is USB plug-and-play codes which tell the host computer which USB driver to use, but there may be other differences. It would be nice to have a single cable that did both so you can use it either way for RasPi.

Re: What have we missed?

Posted: Fri Nov 25, 2011 6:04 pm
by hippy
Quote from kme on November 25, 2011, 15:17
The UART pins are the RS-232 connector (RX, TX and power only).

Serial, RS232-style may be better than calling it "RS232" which has very specific definitions which I don't believe the R-PI will conform with.

The UART pins will be 0V/3V3 and likely be idle high signalling which is incompatible with direct connection to a PC COM port and USB-to-RS232 cables, and connecting them together directlty may even damage the R-Pi SoC.

An inverter and level-shifting will be required ( usually a MAX232 family chip ) to turn UART signals into RS232 signals, but some USB-to-serial cables and modules will be compatible with the UART signals.

The UART pins will also be able to connect to other R-Pi and micros directly ( 3V3 and probably 5V with simple single resistor current limiting ).

Quote from albertfrutos on November 25, 2011, 15:49
I hope more documentation will be provided when the device is launched, including how to connect the COM/RS232 to the board (welding, I suppose) and how to connect it to the computer. I think a full tutorial would be so useful for the newbies :)

For most people wanting to use RS232 with an R-Pi a USB-to-RS232 cable will be what's best to use. Simply plug the USB into the R-Pi and connect the 9-way D to the RS232 device.

Re: What have we missed?

Posted: Sat Nov 26, 2011 11:22 am
by pufik
Hi all! You do great work!!! Thank you!!!

I am so sorry , maybe it is off top, but...
As for me, R-PI it's a excellent solution for most in our every day actions.
Lets think, what we do every day...
First of all, i read emails, news, communicate with friends, listen music, watch videos and images, read articles or books... For this in 80%(or maybe 90%) I use browser and connection to Internet...
I think, all solutions in the future will be solved in WEB. For use this solutions we don't need much resources of computer and for this is excellent R-PI idea.
it is small, cheap and has enough computing resources.
It's is a excellent solution for schools, libraries, universities, colleges and other place where needs many "thin client" to the services that provide organization.
As for me, it's a main purpose for R-PI.
For provide all what a write R-PI B is the best. It has Ethernet, USB and 256Mb of memory. But for best work it must have too:
Hardware:
1. Wi-Fi;
2. More memory. 512Mb will be excellent.
Software:
1. OS. Simple and fast with TCP/IP stack. Linux is excellent solution.
2. Up to date browser. As for me Mozzila will be good for it.
3. Office software. Text processor, different readers(PDF, DjVU, etc) etc.
4. Multimedia software. Players for different formats and Flash player.

Of course R-PI must have some tools for software development. But we must understand that we as programers and engineers produce a product but we must have customers for this product in other way we will do it only for as.

Conclusion
R-PI is an excellent idea.
It will the best when you add:
1. More memory(512mb);
2. Wi-fi.
3. Simple case.
4. SD card with software(os, browser etc).
It will be a ready solutions.
If price will be 50 - 70$ it will be very nice.

P.S. Sorry... But my English is not the best... I hope you understand what i mean.
P.S.S. With best regards, Iurii.

Re: What have we missed?

Posted: Sat Nov 26, 2011 12:53 pm
by abishur
lol, pufik, you definitely get an achievement award: Necromancer (for raising this thread back up)

Obviously at this point in the game (right before launch) none of this will happen on the initial release, but here are some answers to these commonly requested items

1) The r-pi uses a package on package design for it's chip. A 512 MB package doesn't exist for it yet. (at least not at an any where near afford price)

2) Wifi can be added via a wifi dongle for those who desire it

3) They want this one too. But until they nailed down the final design, they couldn't make a case for it.

4) They actually are going to offer this one... Check the FAQs :)

Price issue, the final issue on price is that they need to hit a $25 price limit to fit their goals, as such a 50-70 solution won't work. However, if you're really okay with paying more, check out beaglebaord or pandaboard (maybe even sheevaplug?) they're all more expensive, but they might fit your desires a little more squarely. :D

Also, I think the project is way past "What did we miss" so let's go ahead and close this thread down.

Didn't get to say what you think the r-pi team missed? Read through this thread, someone probably said it all for you ;)

Re: What have we missed?

Posted: Sun Apr 22, 2012 7:33 pm
by egp
in a future version of the board, it would great to have two independent ethernet interfaces, so the board can become a firewall/router.

Re: What have we missed?

Posted: Mon Apr 23, 2012 5:23 am
by rew
As even the first ethernet interface is on USB but soldered on the board, I suggest you get an USB ethernet dongle and use that. Even IF it were designed onto the board, it would still be connected through USB as there is little else to connect to the chip.

You won't break the bank buying one of those:

http://www.ebay.com/itm/Ethern.....3a73705e45

(for the future, when that link goes dead: $3 incl shipping for an adapter.)