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Software Defined Radio, Chapter 2: It Didn't Work

 So now it's 2023 and I haven't revisited the project.  Nothing I did 4 years ago would still apply anyway. CISC has since done this themselves.  Their SDR is painted gold.  Other than that, it's basically what I set out to do in 2017.  Except it works, presumably, so good on them: https://www.cisc.at/product/rain-xplorer-spy/ In Sep2023, I am trying again with the Analog Devices ADL5920 .  It's a $40 chip with bidirectional RF transmission line built in.  It can separate forward from reverse power and measure both independently.  That means, potentially, you could have a VNA in every RFID reader, telling you how good your antenna setup is and whether your antennas are receiving power from neighbors. Hopefully it won't be another 4 years before I post again.
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Software Defined Radio, Chapter 1: The Beginning (for me)

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Sometime in 2003, my boss handed me a textbook about Software Defined Radio and told me I should learn about it.  The company was SAMSys Technologies, an RFID industry pioneer.  I had written the firmware for many of the company's products, but they always used hardware based radios.  I was a hard working professional at the top of my game, but SDR didn't click for me.  At the time it was too theoretical.  Without something real to poke, I got lost real fast. Another thing that happened at SAMSys was that a coworker made a sniffer for UHF RFID that allowed me to view the air interface on an o'scope (I vastly prefer the Agilent MSO with MegaZoom, which lets me capture an entire transaction and zoom in to each bit without recapturing).  That tool was crazy valuable in my RFID reader development at SAMSys because it showed me both forward and reverse link traffic, and even let me see if a tag was responding.  I've tried to duplicate it a few times, but ...
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Welcome to Larry's Lab Blog

Hello and thank you for reading this.  My name is Larry Martin.  By day I'm a tech consultant to the print industry.  By night, now that the kids are grown, I mostly play games or watch TV with my wife Marinda.  But sometimes I get interested in stuff and work late on it.  This blog is my place to geek out on radio, software and other technical topics. Here are older tech blogs of mine: STM32F4 Development and Toolchain Follies Development and Environment Notes on the Digi ConnectMe And this is my company website: GlueLogix Inc., RFID for Label, Card and Wristband Companies Let's see how this goes...
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