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The article is incredibly light on detail. Making 3D printed items with switches in them is really easy. It's the receiver that's the hard part. It would be gr

The article is incredibly light on detail. Making 3D printed items with switches in them is really easy. It's the receiver that's the hard part. It would be great if they actually gave details. I want to know: 1. What device is receiving the signals. Is it commodity hardware (like a phone or laptop) or do they have to build a custom RF receive chain? 2. What software is used? What signal processing do they have to do? How does the software differentiate between one device and another one? The interesting, ground breaking stuff is all in the electronics and software. The 3D printing stuff is fluff - it's just taking 100 year old technology and adding "3D printed" to it to make it seem modern.

jldugger 9y ago
Citations are always a researcher's best friend. The video has a URL researchers, http://printedwifi.cs.washington.edu/ http://printedwifi.cs.washington.edu/. That page has a paper PDF, with the following line: > We note that prior electronic-based designs use both Wi-Fi signal variations (RSSI) as well as channel state information (CSI) variations [Kellogg et al.2014] to extract backscatter data. The backscattered signal from our 3D printed objects can be extracted using either of these procedures. Our implementation uses the MAX2829 802.11a/b/g transceiver that gives us access to the received 802.11g baseband signal. Based on my time in grad school, I'm guessing they custom built a microcontroller for the task, and used that chip. There's a wealth of papers online dealing with backscatter, including the Kellogg paper cited above. Among their proposed setups is this fairly passive one: > Finally, we check the feasibility of using only the periodic beacon messages from the AP. We use an Intel Wi-Fi Link 5300 card configured as the AP and an Intel Wi-Fi Link 5300 card as a Wi-Fi reader. The reader does not generate any traffic on the network and passively listens to the beacon messages periodically transmitted by the access point. No other device is associated with the access point, but it operates on channel 6, which is the same frequency as our organization’s Wi-Fi network. Your other questions may be similar answered by following citations =)

jldugger 9y ago

Citations are always a researcher's best friend. The video has a URL researchers, http://printedwifi.cs.washington.edu/ http://printedwifi.cs.washington.edu/. That page has a paper PDF, with the following line: > We note that prior electronic-based designs use both Wi-Fi signal variations (RSSI) as well as channel state information (CSI) variations [Kellogg et al.2014] to extract backscatter data. The backscattered signal from our 3D printed objects can be extracted using either of these procedures. Our implementation uses the MAX2829 802.11a/b/g transceiver that gives us access to the received 802.11g baseband signal. Based on my time in grad school, I'm guessing they custom built a microcontroller for the task, and used that chip. There's a wealth of papers online dealing with backscatter, including the Kellogg paper cited above. Among their proposed setups is this fairly passive one: > Finally, we check the feasibility of using only the periodic beacon messages from the AP. We use an Intel Wi-Fi Link 5300 card configured as the AP and an Intel Wi-Fi Link 5300 card as a Wi-Fi reader. The reader does not generate any traffic on the network and passively listens to the beacon messages periodically transmitted by the access point. No other device is associated with the access point, but it operates on channel 6, which is the same frequency as our organization’s Wi-Fi network. Your other questions may be similar answered by following citations =)