I made this project as a test to improve a technic to read analog values without analog-to-digital converter. (ADC) I ended with this `sound meter`. It may not work perfectly, it needs some improvement but works anyway. It have the feature of `auto-calibration`, so it detects the signal, amplify it and measures it. Because the `auto-calibration` feature, it doesn't need an amplifier or any aditional circuit to drive the signal from the electret microphone. The capacitor can be a 103k or a 220k. A poliester capacitor works better. The code is compatible con 16F84A or 16F628 so I can't define exactly what value should have. Anyway, If you find this projects interesting, you may be able to experiment with the value of the capacitor.
Click here to download the full size of the above Circuit.
The config should be: INTERNAL RC and PWRT ON for 16F628. For the 16F84A the config is External RC and PWRT ON. As I mention before, the reason of this project is becuse i'm working in a technic to read analog values directly from a signal without an ADC. Here is the method used to read analog values with a digital input output pin: 1. Connect a RC circuit to a Digital I/O pin. 2. Set the pin as OUTPUT and make it high for 1 ms (one milisecond) 3. Set the pin as INPUT and start a 16 bit counter until the input signal is low. The value of the 16-bit counter should be the value of the input signal or the value of the RC. You can learn more about this technic at the Microchip's web page (www.microchip.com) reading the application notes at the documentation section.
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: