Remotly check the temperature of a few things, in my case the repeater site at GB3PY. A system which used a radio to receive requests for the currenttemperature and send the results back to the user. Requests are by DTMF tones and the response is in CW, mores code. The full design has not been tested, but I`ve managaed to do it with 2 sensors which works fine. This is an ongoing project and after a request
Click here to download the full size of the above Circuit.
from a friend about using PICAXE to decode DTMF I thought I would post details of the project which demonstrates the wayI do it. The PICAXE code, schematic and PCB layout are all available todownload below. The code has afew things worth mentioning in it. When the HT9170B DTMF decoder chip gets a valid DTMF tone it outputs the value in binary (check the datasheet) but DTMF 1 outputs binary 1 or 0001 and DTMF 8 outputs binary 8 or 0100. Not only this there is a line called DV, pin 15 on the HT9170B which goes high when a valid DTMF tone is decode, this is great cause it is a way to tell the PICAXE it is time to read the input pins. You`ll see this in the code on line 41 if pin4 = 0 then goto start`. Basically I have a pin set in the code, this is between lines 42 and 72 and if the valid pin is entered then we read the temp and respond. The code below should be enough to read the DTMF value and store is register B0 using just the DTMF chip and PICAXE. so B0 is the actual value of the DTMF key pressed.
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: