Having done half a dozen V-USB tutorials I decided it`s time to whip up something cool. As USB keyboards were an area untouched, I decided to make a small USB HID keyboard device that types a password stored in EEPROM every time it`s attached. A new password can be generated just by tabbing CAPS LOCK a few times (4 times to start password regenera
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tion and one tab for each password character generated, 10 is the default password length). Below you can see the device in action: The place I work at requires me to change my password every few months so this would be one way to skip remembering a new password altogether (as long as I remember to write it down before regenerating a new one so password can be changed :). The device is powered with a simplified version of the hardware I used in my ATtiny85 USB tutorial I stripped away the LCD, reset pullup and both capacitors. If you`re better in cramming components inside enclosures I suggest adding at least a 0. 1 uF capacitor between VCC and GND, but it seems to work fine even without it: The enclosure was graciously donated by an old 512 MB flash drive. I couldn`t make myself to break the USB connector from the circuit board inside, so I stripped appart a short USB cable instead (shown on left): I soldered the connector first, then the zener diodes, then resistors and jumpers, and finally VCC, GND and the ATtiny itself. I used the following tricks to make all ends meet: I was pretty satisfied the result and the fact that it actually worked! The board did not initially fit into the very snug space in the plastic enclosure, so I had to use a Dremel to trim its insides a bit, but after that, everything snapped right back (click for larger versions): Update: For those who are building this project I recommend you first...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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