The physical world is analog and if we want to interface with it using a digital device there are conversions that need to be made. To do this we use an Analog to Digital Converter (ADC) for translating real world analog quantities into digital values. But we can’t just dump any analog signal into the input of an ADC, we need this analog signal to be a measurable voltage that’s clean and conditioned. Meaning we’ve removed all the noise and converted the measured value into a usable voltage.
Things That Just Work.
This is not new information, least of all to Hackaday readers. The important bit is that we rely on these systems daily and they need to work as advertised. A simple example are the headlights in my car that I turned on the first night I got in it 5 years ago and haven’t turned off since. This is not a daytime running lights system, the controller turns the lights on when it’s dark and leaves them off during the day. This application falls into the category of things that go largely unnoticed because simply put: They. Work. Every. Time. It’s not a jaw dropping example but it’s a well implemented use of an analog to digital conversion that’s practical and reliable.
Sometimes along comes a machine so simple yet so alluring in what it does and how it achieves its aim that you just want one. Doesn’t matter what it does or indeed whether ownership is a practical proposition, you wish you could have one in your possession.
What machine could trigger this reaction, you ask? [Robbie Van Der Walt] and [Christiaan Harmse] have the answer, their machine performs the simple but important task of cooking an endless pancake. A hopper dispenses a layer of pancake batter onto a slowly rotating heated roller that cooks the ribbon of pancake on one side, before it is transferred to another roller that cooks the other side. It seems simple enough yet the simplicity must hide a huge amount of product refinement and probably many miles of lost pancake. Pancakes it seems are a traditional South African delicacy, evidently they must have king-sized appetites to satisfy.
Maybe you suspected this already, but researchers at MSU Computer Science just published a paper explaining just how easy it is to spoof a fingerprint scanner with a ink-jet printed scan of a finger.
We’re not talking about casting a new finger using superglue or anything, but rather using conductive ink you can literally print — on paper. A paper-printed-fingerprint that will unlock your smartphone. We’ve already told you fingerprints suck for security, but hopefully this drives the point home.
[Kai Cao] and [Anil K Jain] released this paper (Direct PDF link) outlining their technique. Using an existing scan of a fingerprint (which can be taken from your phone’s scanner), the image is mirrored, and then printed using a regular ink-jet printer, with all of its color cartridges replaced with AgIC4 silver conductive ink. Continue reading “Finger Print Scanners Really Aren’t That Secure”→