A Spectrum Analyzer For The Smart Response XE

Remember the Girl Tech IM-me? It was a hot-pink clearance rack toy that suddenly became one of the hottest commodities in the hacking world when it was discovered they could be used for all sorts of radio frequency shenanigans. Now they go for triple digits on eBay, if you can even find one. Well, we’re probably about to see the same thing happen to the Smart Response XE.

Thanks to the work of a hacker named [ea], this cheap educational gadget is finally starting to live up to the potential we saw in it back when a teardown revealed it was powered by an Arduino-compatible ATmega128RF chip. With a big screen, a decent QWERTY keyboard, and integrated wireless hardware, it seemed obvious that the Smart Response XE was poised to be the next must-have repurposed piece of kit.

Though as it turns out, [ea] isn’t using the device’s built-in wireless hardware. Step one in this exceptionally well documented and photographed project is to tack a CC1101 transceiver module to the SPI pins on the ATmega128RF. Then with the appropriate firmware loaded up, that nice big screen will show you what’s happening on the 300 MHz, 400 Mhz and 900 MHz bands.

But the fun doesn’t stop there. With the CC1101-modified Smart Response XE, there’s a whole new world of radio hacks you can pull off. As a proof of concept, [ea] has also included a POCSAG pager decoder. Granted the RTL-SDR has already made pulling pager messages out of the air pretty easy, but there’s something to be said for being able to do it on something so small and unassuming.

If you can’t tell, we’re exceptionally interested in seeing what the community can do with the Smart Response XE. At the time of this writing, the going rate on eBay for a good condition unit looks to be about $10 USD, plus the $3 or so for the CC1101 module. But the prices went through the roof when we first posted about it, so get them cheap while you still can.

[Thanks to bburky for the tip.]

25 thoughts on “A Spectrum Analyzer For The Smart Response XE

  1. Really? The Girl Tech IM-me is up to tripple digits now? OMG!

    Guys.. this IS a cool hack but before you all drive this one up that far remember you can get an old cellphone or tablet and an RTL-SDR stick for only a 2-digit price and you even get a much wider frequency range along with it.

    1. The point is that this is a small, portable, and cheap (at least, for now) device that can do a lot of the same kind of RF tasks that would normally require a much more awkward setup. That’s where the value is.

      As the software library for this grows, it will be a very valuable tool.

      1. I’m not arguing. This is a nicer form factor than a cellphone or tablet with an RTLSDR dongle. It’s just not THAT much nicer so as to be worthwhile if the price jumps up unto the 100s of dollars[US] range.

    2. I had the same reaction to the IM-me price. Makes me wonder if it’s time to sell the one I have sitting on the shelf.

      But I’m also reminded of what I constantly tell my kids. You can charge what you want but it’s only worth what someone is willing to pay.

  2. Oh, Hackaday… I have a lot of 40 of these in my basement from when these came up last year. AND one of the VTech tablets mentioned last week arrives today. One of these days, I will do something with them…

  3. Unfortunately, eve if their prices are (for a little time ) low on ebay, shipping still kills it around here. Will need to keep an eye on local appliances with screens, though. One never knows what can appear and be useful …

  4. RTL-SDR will work with a phone too. Old or new android. The hack is brilliant. Practically speaking though, a simpler, more powerful, and compact solution is available to all of us.

  5. I looked at the pictures of the PCB and it seems to me that the unpopulated serial port level converter might be an ICL3221.
    If so, it’d be easy to add that chip plus a few capacitors to the PCB and then have access to RS232 level serial port.

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