SparkFun Forums

[raphaelfc]

Hi,

I came across this post (http://www.glacialwanderer.com/hobbyrobotics/?p=291) and i wanted to use the same set up without the Arduino on the transmitter side. So i thought of using this (http://www.sparkfun.com/commerce/produc ... cts_id=437) and this (http://www.sparkfun.com/commerce/produc ... ts_id=8945) to build a USB RF Transmitter Dongle and communicate to the receiver using it via a serial port (COM3) on the PC (Java RxTx). Is it that simple or there's something else that i need to do in order to put it to work that i'm not aware of? Would i have to write, or download if it already exists, a driver so the PC recognizes the dongle? Would i have to use some other component(s)? Please, help on this.

Thanks in advance.

[60amp_relay]

I like it. You'll need one more piece to complete the puzzle:

http://www.sparkfun.com/commerce/produc ... cts_id=650

The USB protocol is too high-level (and too fast) to send directly over that transmitter. What the FT232RL chip does is encapsulate all the USB stuff and simplify it down to a minimal UART interface that the RFLink can easily talk to. It shows up on your PC as a new COM port.

Good luck!

[raphaelfc]

Holy crap, how do i connect this bridge? Is there any tutorial?

[60amp_relay]

So far, the best way I've found is to buy the pre-assembled breakout board: http://www.sparkfun.com/commerce/produc ... cts_id=718. You'll need to configure it for +5V by unsoldering the +3.3V jumper.

Here's an example on a breadboard (attached).

[raphaelfc]

That's exactly what i was looking for. Isn't there any other information where you found this picture? So, once i set this up the pc will recognize it as a COM port? This easy?

[EDIT]

For those who are interested in the answers of my questions, here they are.

If you are going to use this breakout board 60amp_relay commented (http://www.sparkfun.com/commerce/produc ... cts_id=718) you're going to have to install the driver (http://www.ftdichip.com/FTDrivers.htm) on your PC. Once this is done plug your USB cable and it shows up as a COM port (as said before by 60amp_relay).

Now comes my newest doubt. What should i do to use a USB Male Type A connector (http://www.sparkfun.com/commerce/produc ... cts_id=437) instead of the mini USB that comes with the breakout board? Just unsolder the old one and solder the male connector into the corresponding pins will do the job?

[raphaelfc]

It came to me that instead of creating an one way RF USB Dongle, a can create a two ways (transmitter and receiver) and use it in several other projects that use radio frequency communication.

BTW, i still need an aswer to my previous question. Anyone? 60amp_relay, you there?

Thanks.

[60amp_relay]

That's a picture of my own breadboard - I've been using the ft232rl and rflink parts a lot lately, so I just snapped a photo and uploaded it. The mini-USB connector on the ft232rl breakout board is a surface-mount part. I'm not sure how easy it would be to unsolder it, and you couldn't really put a full-size, through-hole USB port there anyway (no space, and no holes). They do make USB -> miniUSB adapters. Two-way comms should work fine if you have a 315MHz pair for transmitting and a 434MHz pair for receiving, or vice versa.

There are also USB <-> bluetooth transceivers that do something similar to what you're trying to achieve here.

[raphaelfc]

60amp_relay, thanks for the reply.

As you said size can be a problem to change the connectors. So, as an alternative i'm probably going to use an adaptor like this http://t2.gstatic.com/images?q=tbn:halu ... iniUSB.jpg to get the job done.

Another thing, i didn't realize until you said that in order to build a two way plug i'm going to have to use different frequencies for the transmitter and the receiver. It sounds obvious now but i didn't see that before.

I'll keep this post alive with my progress until i get the dongle fully functional, someone may want to build a similar one. But, first things first, i'll have to order the components.

60amp_relay, thanks again.

[raphaelfc]

Just ordered the components.

[raphaelfc]

Parts have arrived. Posting progress soon.

[raphaelfc]

Final result can be found here.
http://arduitter.blogspot.com/2010/10/r ... aging.html