This project demonstrates a number of aspects of the PIC16F687 microcontroller, like: ultra low power wake up, serial communications, nanowatt technology etc. The device can be used for different purposes. For example: measuring the content of a rain water tank, of a water tank in a motor home or trailer, and so on. Place the sensor wires in the t
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ank. After putting the batteries, you should see the content on the bar-graph display (between 1/8 and 8/8). After about a minute the display will switch itself off. You can switch back on again at any time by shortly pressing the button. To switch back off, press and hold the button for more than 1 second. Once an hour the display will put itself on for a few seconds, while this is happening the device will also transmit the measured value using RF (433. 92 MHz) (optionally). The transmitter/measuring module can be used by itself or in combination with an optional receiver module (wich operates on 230 VAC). This receiver module can be placed in a radius of 30 meter around the transmitter/measuring module. Diode D2 is for protection against reverse polarity of the batteries and also for lowering down the supply voltage somewhat. Two lithium batteries are supposed to deliver 6 volts, but in reality this will be about 6. 2 volts with new batteries, the voltage drop over the diode will bring this voltage down to about 5. 7 volts which is acceptable for the PIC and the other chips. So we don`t need to use a voltage regulator IC (which would consume more power). Because measuring fluids with the aid of DC current will lead to electrolytic effects and corrosion problems, in this device we will use a measuring current consisting of an AC block wave with a frequency of about 10 kHz. The circuit`s main purpose is measuring the level...
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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