Archive for the 'arduino' Category


Part 1: XRF, Bee Adapter v1.4 and Arduino

Trying to slowly assemble the hardware to build a quadcopter (sigh), I got myself a pair of Ciseco’s XRF modules and a Xbee USB Dongle (Bee Adapter v1.4).

XBee Adapter Back

XRF and XBee Adapter

(You can read more about the XRF modules here:

The Ciseco XRFs are nice little buggers, they work at various frequencies, in the 1KHz range. I find this great because it’s far away from the 2.4GHz noise (microwave, wireless phone stations, wifi and bluetooth). Sure, it may be illegal or require a license in your country but who cares? (Actually, readers that live in more developed and orderly parts of the world, YOU should…)
The XRFs are very nice, since they have the form and pins of the Zigbees (Xbees, whatever), so you practically can use one wherever you’d use a Xbee. Just for a much lower price and various frequencies.

Since my project involved sometime being able to use an Android Phone with the XRFs, I bought the Bee Adapter from, which has serial and usb access. The Arduino I had bought a while ago, just upgraded it with a prototyping shield.

Notice something is missing? Yeah, it so happens that I completely forgot that to do anything with the modules, I’d need to connect the TWO of them. But I only bought one adapter. Genius, right?

Even so, they finally arrived. Shipping from the UK to Brazil is actually quite fast. From HK or US it’d probably get stuck in customs for a while…

The Bee Adapter was a bit different from the picture at DX, though seemed legit. Got two toggles that let you choose between High/Low, which seems to be power consumption, and 3v3/5v.

XBee Adapter Back

XBee Adapter Back

So! Let’s connect’em… Power levels fail via usb… power status led barely shines with the XRF module… Hmmm, XRF module must be using a lot of power! (shouldn’t but who knows..) So I plugged it in my newest Prototyping shield, wired up the serial connectors and blam… It worked fine with the Arduino. Tested it for the +++ command which get’s it to enter the config mode, it sends OK.

XBee Adapter Back

Arduino with Prototyping shield, Xbee Adapter and XRF module.

Great little adapter doesn’t work via USB… I’d guess it needs a current limiter, didn’t care to debug it…

Aaaaand there was the need for the other adapter more than ever, specially because the Xbee modules pins are not breadboard compatible…yay…


New addition: Arduino

W00t! My new and only arduino just arrived!

Ordered it from eBay(HK, cough cough) instead of buying it here in Brazil. Obvious choice because it would cost me 62.6 USD instead of the 15 I payed.

I bought the Duemilanove, discovered later I should have bought the UNO, which has the ATmega8U2 instead of the FTDI to communicate via USB. This is better because the ATmega8U2 is programmable, so you could make it act as any USB device instead of just a virtual com.

Getting started is ridiculous, in ubuntu at least. Just download the arduino software available at, extract and run.

Select your board in Tools, and other minor configurations, paste the LED Tutorial(also available at the official site) onto the sketch and upload. There! Your first arduino code running!(Note that the 2009 already comes with a LED connected to the pin 13, no need to connect another)

The interesting thing is, the USB-TTL used to program the arduino can be used to communicate with your code that’s running inside the arduino! When using this feature, the pins 0 and 1 (digital), which are named RX and TX respectively, are/can be used to connect a serial ttl device directly to the computer.

Why is this so nice? I bought a bluetooth TTL module which I plan to connect to the arduino and make it talk to android!


Further ramblings:
With the launch of the ADK(Open Accessory Development Kit for android, which is basically an arduino with various sensors) you can now connect it via usb on the android an do all sort of stuff.

With a non-official ADK arduino, you must make use of the USB-Host shield and use the new lib.

First, ADK should be able to be host OR client, depending on the power source. Don’t know if the USB-Host shield supports this and/or the android device must be able to provide power via the usb interface. I should look into it… someday.

Second, the arduino UNO allows for USB device ’emulation’. Is the USB-Host shield really needed or could the ATmega8U2 be programmed to act as an ADK device/proxy?



So, a new hope a new turn. I should be posting stuff about the arduino and what I’m trying to do with it in the not that near future.

Some other posts are coming along slowly, when I have the opportunity to write. Must stop procrastinating!

The Author

Older Ramblings


Linux User Sig