Most of the source code of this project its based on my Telecard reader projectof my web site. The components for this project arefew and ordinary, thatmeans low-cost and easy-to-be-found. The `keys` are empty or not telecards (Phone cards. Not cell phone SIM cards), that can befounddiscarded on any telephoneboothwith no additional charge. To learn more
Click here to download the full size of the above Circuit.
about telecards read the phonecards_204. zip. This circuit doesn`t write any data to the telecard. The ATtiny26 reads the 16 first bytes of telecard and then store them in to the internal eeprom of ATtiny26. When you insert any telecard in to the telecard holder (telecard`s slot) will be pressed the switch SW1. The ATtiny will seethat a card was inserted in to the slot and reads the card. Temporary will save the 16 first bytes of the card to the RAM and after that the ATtiny will search in to its internal eeprom to see if this telecard wasregistered to the system. if not, it will turn-on the Red LED. The ATtiny has 8 groups of 16 bytes each, summary 8*16=128 bytes of eeprom memory. With any telecard in to the slot, press the SW2 forregistering the card in to the system. The ATtiny will search the internal eeprom for empty memory group (1 group=16 bytes with $0F values). If there is empty group, it will read the 16 bytes from RAM and store them to the eeprom. Then, the ATtiny will reboot, reset the telecard, read it again and check if the card is registered (by compare the 16 bytes of telecard, with 1 group at the time, with internal eeprom). Now it will turn-off the Red LED and turn-on the green LED because we have registered this telecard in to the system. At the same time it will arm the relay connected to PB6 pin via BC547. If for some reason youdon`t want to use any of the 8 registeredtelecard, youcan un-register it...
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.....
characters left: