Schlagwort: scanner

  • Use an LED matrix as a scanner

    Use an LED matrix as a scanner

    Reading Time: 2 minutes

    Use an LED matrix as a scanner

    Arduino TeamMay 1st, 2019

    Consider that a digital camera uses an array of sensors to capture light from an object. Maker Marcio T, however, decided to turn this idea on its head and instead utilize an array of lights that are detected by a single sensor.

    The way it works is that as each LED in a 32×32 matrix illuminates, a phototransistor picks up light if the path is clear or sees no change if the path is blocked. So when you put an object on the matrix, the sensor is able to get an accurate picture of it, enabling its Arduino Uno controller to then generate its silhouette. 

    It’s a simple yet very clever hack, and if you pay close attention in the video below, you can see the lights scanning from the bottom to top before the image is produced.

    Ordinary digital cameras work by using a large array of light sensors to capture light as it is reflected from an object. In this experiment, I wanted to see whether I could build a backwards camera: instead of having an array of light sensors, I have just a single sensor; but I control each of 1,024 individual light sources in a 32 x 32 LED matrix.

    The way it works is that the Arduino illuminates one LED at a time, while using the analog input to monitor changes in the light sensor. This allows the Arduino to test whether the sensor can “see” a particular LED. This process is repeated for each of the 1,024 individual LEDs rapidly to generate a map of visible pixels.

    If an object is placed between the LED matrix and the sensor, the Arduino is able to capture the silhouette of that object, which is lit up as a “shadow” once the capture is complete.

    [youtube https://www.youtube.com/watch?v=9F9EUaXhj5M?feature=oembed&w=500&h=281]

    Website: LINK

  • Barcode reader for visually impaired shoppers

    Barcode reader for visually impaired shoppers

    Reading Time: 3 minutes

    To aid his mother in reading the labels of her groceries, Russell Grokett linked a laser barcode reader to a Raspberry Pi Zero W to read out the names of scanned item.

    RASPBERRY PI TALKING BARCODE READER

    My mom is unable to read labels on grocery items anymore, so I went looking for solutions. After seeing that bar code readers for the blind run many hundreds of dollars, I wanted to see what could be done using a Raspberry Pi and a USB Barcode reader.

    Exploring accessibility issues

    As his mother is no longer able to read the labels on her groceries, Russell Grokett started exploring accessibility devices to help her out. When he came across high-priced barcode readers, he decided to take matters into his own hands.

    Camera vs scanner

    Originally opting for a camera to read the codes, Russell encountered issues with light and camera angle. This forced him to think of a new option, and he soon changed his prototype to include a laser barcode reader for around $30. The added bonus was that Raspbian supported the reader out of the box, reducing the need for configuration — always a plus for any maker.

    A screenshot from the video showing the laser scanner used for the Raspberry Pi-powered barcode reader

    Russell’s laser barcode scanner, picked up online for around $30

    No internet, please

    With the issues of the camera neatly resolved, Russell had another obstacle to overcome: the device’s internet access, or lack thereof, when his mother was out of range of WiFi, for example at a store.

    Another key requirement was that this should work WITHOUT an internet connection (such as at a store or friend’s house). So the database and text-to-speech had to be self-contained.

    Russell tackled this by scouring the internet for open-source UPC code databases, collecting barcode data to be stored on the Raspberry Pi. Due to cost (few databases are available for free), he was forced to stitch together bits of information he could find, resigning himself to inputting new information manually in the future.

    I was able to put a couple open-source databases together (sources in appendix below), but even with nearly 700000 items in it, a vast number are missing.

    To this end, I have done two things: one is to focus on grocery items specifically, and the other is to add a webserver to the Raspberry Pi to allow adding new UPC codes manually, though this does require at least local network connectivity.

    Read it aloud

    For the text-to-speech function of the project, Russell used Flite, as this interface makes a healthy compromise between quality of audio and speed. As he explains in his Instructables tutorial, you can find out more about using Flite on the Adafruit website.

    A screenshot from the video showing the laser scanner used for the Raspberry Pi-powered barcode reader scanned an item

    When an item is scanned, the Raspberry Pi plays back audio of its name

    In order to maintain the handheld size of the scanner, Russell used a Raspberry Pi Zero W for the project, and he repurposed his audio setup of a previous build, the Earthquake Pi.

    Make your own

    Find a full breakdown of the build, including ingredients, code, and future plans on Instructables. And while you’re there, be sure to check out Russell’s other Raspberry Pi–based projects, such as PiTextReader, a DIY text-to-speech reader; and the aforementioned Earthquake Pi, a light-flashing, box-rattling earthquake indicator for your desk.

    Website: LINK

  • Amazing Technology That Can Extract 3D Objects from 2D Photos

    Amazing Technology That Can Extract 3D Objects from 2D Photos

    Reading Time: < 1 minute

    Always wanted to created real 3D models from flat 2D pictures? If so, then „3 Sweep“ is just for you. Users will not only be able to „just extract them, but then manipulate them, transform them, copy them, and move them around the image.“

    You get the feeling that this is still in its early developmental stages, so there are some visible limitations. But in terms of what it’s capable already, we’ve never seen anything like it.

    If Adobe doesn’t have their eye on these guys, they’re making a big mistake.

    Official Source: LINK