The output assign modules uses a 16V8 GAL for address decoding and enable signal generation. Figure 44 shows the pin assignments for the GAL used in the output assign module. The VHDL code used to generate the GALs is included in the appendices, on page The status of 18 pushbutton switches need to be sensed by the microcontroller. Many methods exi
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st for connecting switches to a microcontroller bus. To keep parts count and CPU use down, simple latches are used to latch the status of eight switches at a time. Firmware debouncing routines shall take the place of hardware debouncing techniques. The lack of a multiplexing scheme means less CPU time is wasted in reading in the values of the switches, while the firmware debouncing routines mean fewer components are used on the board. Figure 45 shows the circuit used to achieve these goals. Three of these circuits are present, providing a total of 24 pushbutton inputs. Six of these inputs are used for pushbuttons in the universal user interface and cue stack sections of the control board. Figure 45: Output assign module, momentary pushbutton decoding schematic. The output assign module uses three of these circuits, for a total decoding capability of 18 on-board and 6 off-board buttons. The output assign module contains several LED indicators that need to be controlled by the microcontroller. A simple current-sinking scheme involving 74LS373 octal latches is used, identical to that of the fader module. Figure 46 shows the circuit. The output assign module contains a pair of 7-segment LED displays, controlled by the microcontroller. While it certainly would have been possible to drive the displays in a similar fashion to the bare LEDs present on the same board, this was decided against due to the extra bus ports needed....
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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