I am planning to make my own Arduino (The Coreduino or sanguino specifically), and I notice that there are the following interface:
-Arduino serial USB board
-4-pin FT232RL Break out board
-FTDI Basic breakout (6-socket)
-USB to TTL Adapter
-Lilypad USB Link (4-socket)
What are the differences?? Also, How does a nromal USB to RS232 fits in?
I'll take a stab at this...
The ATMEL cpu only talks 5volt TTL serial.
The question is how do we get that type of signal to the ATMEL cpu. Any method is as good as any other.
we can:
Use a max232 RS232-to-TTL chip to drop the 12volts from your PC com port down to 5volt TTL
OR
Use an USB to TTL chip.
Many if not all of the various usb solutions are identical except for the packaging and cable connector. In the end, it is a common USB-to-TTL converter with a plug. Newer arduino boards went 1 step further and soldered the usb-to-TTL-serial chip onto the main board.
FTDI makes the chip.
I think the part number is something like the FT232 you quoted.
TTL is the type of signal it emits to the CPU.
Different systems (non-arduino) have different connectors. Many of the generic converters have connectors with the same signals but on different pins (as you mentioned).
The most basic communications board has send/receive/ground (3 pins). Then they added the reset wire (now we have 4 pins). Some also added external power pins (now we have 6 pins). But in the end, you could still work with only a 3 wire converter (but the 4 wire mode is a wee bit better - auto reset).
PS: The generic USB to Serial cables that you can buy at a computer store use almost the same chip as the arduino. That means those generic usb-serial dongles from BestBuy/Futureshop are not required because it is already there on the arduino unless you decided to build a rs232 version. In that case, the max232 chip is doing the conversion and you plug into your PC comport (or use one of those dongles if you do not have a com port on your pc/laptop).
I see. So Basically, for breadboarding, I would probably need the Arduino USB board, the 4-socket type for Lilypad, and 6-socket for the conventional FTDL interface, right?
Well for best use with a breadboard a Arduino compatible board designed to plug into breadboards is somewhat easier to work with. Check this baby out, nice price too.
well, I was more like planning to build my own arduino/Coreduino/Sanguino.
If breadboarding, I would buy the cheapest USB to serialTTL converter possible without regard to the connector since you would use hookup wire on the breadboard to go to the correct pin on the converter.
Some of these tiny usb boards have connector plugs that exactly mate certain types of arduino boards. If you have the 'wrong' usb board, de-solder the connector and solder a short cable with the correct connector on the end.
The 2 boards below are the same thing, just different pin layouts.
http://www.hvwtech.com/products_view.asp?ProductID=926
http://www.4dsystems.com.au/downloads//micro-USB/uUSB-MB5/Docs/Pdf/uUSB-MB5_DataSheet_rev1.pdf
my problem with the http://spiffie.org/kits/iduino/ board is it is expensive as compared to making your own without a usb chip and only plugging in an external chip as required.
I suppose I do not know what you mean about making your own. Do you mean a kit or simply putting a CPU+crystal on a breadboard.
This company has some nice stuff, buy the bare DC boards if you want cheap!
For a good general purpose, breadboard friendly, USB/serial module based on the FT232RL chip, I bought this one from Spark Fun. Mostly because it breaks out every possible signal pin from the RL chip.
Maybe not the cheapest or smallest module avalible but I think the best breadboard ready model. Easy to change the TTL voltage level and I also like the smaller USB B connector used.
I have to admit I have purchased the same one for the same reason.
Nice board if you are breadboarding.