Sadly, Useful Sensors seems to have pivoted to other edge AI tech and no longer sells this or their person detector.
Yeah, that is a shame. Couldn't find something similar unfortunately.
Tiny Code Reader: a $7 QR code sensor
21–30 of 44 posts
Re: Tiny Code Reader: a $7 QR code sensor
#22I've had a recurring idea in my head of a sensor you could mount in your car, and then be able to read QR codes from the side of the road, and get an index of all the businesses you'd be driving by for later lookup. Not sure how feasible or useful it'd actually be...
Re: Tiny Code Reader: a $7 QR code sensor
#23I've had a recurring idea in my head of a sensor you could mount in your car, and then be able to read QR codes from the side of the road, and get an index of all the businesses you'd be driving by for later lookup. Not sure how feasible or useful it'd actually be...
Would you genuinely want this? I personally can't see why. Perhaps at conventions it could be useful as it's hard to visit every table.
Re: Tiny Code Reader: a $7 QR code sensor
#24That's inexpensive enough to be the basis for a modern recreation of the CueCat: https://en.wikipedia.org/wiki/CueCat
#Qcat?
Re: Tiny Code Reader: a $7 QR code sensor
#25I've had a recurring idea in my head of a sensor you could mount in your car, and then be able to read QR codes from the side of the road, and get an index of all the businesses you'd be driving by for later lookup. Not sure how feasible or useful it'd actually be...
That seems easier to do by using OpenStreetMaps and a GPS trace. You would need the businesses to cooperate by putting a QR code out, so they might as well cooperate and keep a maps listing up to date.
I could imagine maybe OCRing the results from a line-scan camera. That would read all the business signs and street names as you drive by them.
Re: Tiny Code Reader: a $7 QR code sensor
#26I've had a recurring idea in my head of a sensor you could mount in your car, and then be able to read QR codes from the side of the road, and get an index of all the businesses you'd be driving by for later lookup. Not sure how feasible or useful it'd actually be...
Why would I want to have this? No idea, but if I did I probably would use a modern dashcam (these can easily do 4K HDR with 60 fps nowadays) and later analyze the recording with OpenVC.
Some viofo dashcams even allow the connection of two secondary cams (those only FullHD) so you could scan to the left and right simultaneously to the front.
Re: Tiny Code Reader: a $7 QR code sensor
#27I've had a recurring idea in my head of a sensor you could mount in your car, and then be able to read QR codes from the side of the road, and get an index of all the businesses you'd be driving by for later lookup. Not sure how feasible or useful it'd actually be...
Reminds me of one of the ideas I heard about for how to do road navigation before GPS - you paint a bunch of barcodes on the road that your car reads as you drive over them, and then your computer figures out where you are (you would probably use dead reckoning with your car's speed and time, too).
Re: Tiny Code Reader: a $7 QR code sensor
#28Somewhat incidentally, is there an actual description of how a low-tech QR code reader would work? I’ve looked for this a few years ago and all solutions I could find were of two flavours: (1) use ZXing (“Zebra Crossing”, a now-unmaintained library[1] for every 1D and 2D barcode under the sun); (2) use OpenCV. Nowhere could I find any discussion of how one would actually deal with the image-processing part by hand. A…
Using https://duckduckgo.com/?q=qrcode%20decode%20by%20hand gives me a number of results like
http://blog.qartis.com/decoding-small-qr-codes-by-hand/
https://beck-thompson.github.io/QRcodewebsite/
Reading QR codes without a computer! https://qr.blinry.org/
And then there are a number of OSS implementations for Android (check fdroid.orgl, Debian/Ubuntu, etc. Maybe study the code?
Re: Tiny Code Reader: a $7 QR code sensor
#29A fridge-mounted ESP32 barcode integration would be pretty awesome for tracking fridge inventory
Re: Tiny Code Reader: a $7 QR code sensor
#30Somewhat incidentally, is there an actual description of how a low-tech QR code reader would work? I’ve looked for this a few years ago and all solutions I could find were of two flavours: (1) use ZXing (“Zebra Crossing”, a now-unmaintained library[1] for every 1D and 2D barcode under the sun); (2) use OpenCV. Nowhere could I find any discussion of how one would actually deal with the image-processing part by hand. A…
Using https://duckduckgo.com/?q=qrcode%20decode%20by%20hand gives me a number of results like http://blog.qartis.com/decoding-small-qr-codes-by-hand/ https://beck-thompson.github.io/QRcodewebsite/ Reading QR codes without a computer! https://qr.blinry.org/ And then there are a number of OSS implementations for Android (check fdroid.orgl, Debian/Ubuntu, etc. Maybe study the code?
That’s not what I’m asking about: once you’ve found the QR code in the bag of pixels you got from your camera and converted it to a boolean array of module colours, then yes, all you have left is a bit error-correction math and some amusingly archaic Japanese character encoding schemes—definitely some work, but ultimately just some work. (For that matter, the Wikipedia article on QR codes contains enough detail to do this.)
What has thus far remained a mystery to me is going from a bag of noisy pixels with a blurry photo of a tattoo on a hairy arm surrounded by random desk clutter to array of booleans. I meant “by hand” as in “without libraries”, not “using a human”, as in the latter case the human’s visual cortex does the interesting part! And the open-source Android apps that I’ve looked at just wrap ZXing, which is huge (so a sibling commenter’s suggestion of looking at a different, QR-code-specific library is helpful).