The design is based on the previous analysis of calculating the game in a circular shift register. While designing, it occurred to me that small extensions to the design would enable additional game play features, such as replay and manual input. The final design has the following features: The system clock is a low frequency relaxation oscillator
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with a `14 Schmitt trigger, running at about 13kHz. The frequency has been chosen to give a scan-cycle time of ~20ms for the keyboard scanner. The clock is combined with the first two stages of a `4040 and a `238 de-multiplexer into a phased clock signal (PHASE0, PHASE1 and PHASE2), which are guaranteed sequential, separated and non-overlapping. A phased clock assures that events can be timed precisely in sequence and prevents glitches from propagating (CPUs use a similar method internally too). The clock phase generation is coupled with the keyboard scanner (see below). The system is initialized by a common reset circuit setup using a RC charge time coupled to a `14 Schmitt trigger. When the power is turned on, the RC delay holds all important pins at the reset level (CLEAR signal) and thereby initializes the logic to start in a known situation. The reverse diode (D71) is connected to prevent any latch-up when power is `wonky` (input pins should never be allowed to be at a higher level than the power-supply). The board initialization for each new game is taken from an adjustable random generator. The source of random is a PN-junction in reverse (Q1 base-to-emitter). A high voltage applied at the PN-junction forces it into avalanche breakdown, but when this happens, the applied voltage is reduced through Q2 becoming active (the BE junction of a BC547B starts to break down between 7 and 8 Volts). The output of Q2 is...
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....
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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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