Now, let`s re-examine the function of the TRIS registers. The TRISA and TRISB registers control the direction of data transfer on each pin of Port A and Port B, respectively. The easy way to remember the TRIS register settings is to match the numbers 0 and 1 to the letters O and I: The CHRP circuit board includes a number of input circuits, such a
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s pushbutton switches, phototransistors (light sensors), and a potentiometer (position sensor). All of these inputs operate in a similar, though slightly different way. Examine the switch input schematic diagram, below: The switch (S1) and pull-up resistor (R1) form a series circuit, also known as a voltage divider. The microcontroller input is connected to the output at the mid-point of the voltage divider, and senses the electrical potential across the switch. Since any microcontroller pins configured as inputs have a high impedance, they will just sense the externally applied voltage but won`t conduct any appreciable current themselves. This essentially means that the effect of the series resistor (R2) between the voltage divider and the microcontroller is negligible and can be safely ignored ”R2 is installed to limit the current due to ESD (electro-static discharge), protecting the microcontroller from static charges conducted into the switch circuit by a user`s fingers. Ignoring R2, the operation of the switch input circuit can be explained by the interaction of the switch and pull-up resistor R1. You can think about how this works either by Ohm`s law analysis, or by thinking about it as a voltage divider. Using Ohm`s Law analysis, we know that when the switch is open, no current flows through the pull-up resistor. Since no current flows, the voltage loss across the resistor is zero, and the microcontroller input pin...
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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