A rotary encoder, also called a shaft encoder, is an electromechanical device that converts the angular position or motion of a shaft or axle to an analog or digital. Step 6 Conclusion This new technique of measuring distances is a great alternative to conventional laser methods. But the largest advantage is that you can measure. HDMI Cables maplin. HDMI male to HDMI male cable. Read More 1. 0 metre HDMI male to HDMI male cable, Lifetime warranty, Premium heavy duty nylon braided cable for added durability, High quality gold plated connectors with full metal jacket, Triple shielded, Compatible with 3. D, 4. K 6. 0Hz and HDCP signals. Why use HDMI HDMI. View product. Read Less. Radio Shack Products by Part Number. Below is a list of all the Radio Shack products, derived from Radio Shacks website. The list is sorted by Radio Shacks SKU or. Distance Measurement With Radio Waves 7 Steps with PicturesIntroduction Distance Measurement With Radio Waves. Introduction First of all, we want to excuse us for our bad English. German pupils DWe invented a new, inexpensive device to measure distances up to 1. Meter 1. 5 feet. The use of radio waves makes it possible to measure without the target being in sight. This means, you can measure distances through whole buildings. There are many rangefinders available, which are working with sound waves or lasers. A disadvantage of distance measurement with laser rangefinder is that you must center up the beam to the receiver and ensure that there are no obstacles along the laser beam. Schematics and layouts are 1. We already took part with this project in a German youth science competition called Jugend Forscht and won the 1st prize. Step 1 Step 1 Basic Idea. Step 1 Basic idea. To put it simply, the main part is an exact stopwatch, which measures time with a resolution in nanoseconds. It is used to stop the time the emitted radio wave is travelling. Because the spreading rate of radio waves is identical with velocity of light, you can calculate the distance between the two devices measuring points by a given travel time of the radio waves. The stopwatch contains a crystal with a clock rate of 3. Megahertz and a couple of decade counters High Speed CMOS. To display the stopped time, binary outputs of the decade counters must be converted to be easier readable on 7 segment displays. The process of a single measurement 1 The measurement is being initiated started with a button by the user at the basic station 1st point2 Counter starts, at exactly the same time a 4. MHz AM transmitter module emits out a 1st radio wave. The radio wave gets into the receiver at the 2nd point, and immediately starts the 2nd transmitter at a frequency of 8. MHz. 4 The 8. 68 MHz wave is being received at the basic station and stops the counter. The travelling time can be read on the display. FJH/65KX/IGFGO7BM/FJH65KXIGFGO7BM.MEDIUM.jpg' alt='Laser Range Finder Serial Output' title='Laser Range Finder Serial Output' />Step 2 Step 2 Calculation of Distance. Step 2 Calculation of Distance. The formula s t c 2s Distance in mt Wave travelling timec Speed of light 2. HTB1IlM.X7fb_uJkHFrdq6x2IVXaK/40-m-precision-laser-distance-sensors-2mm-ranging-range-finder-module-alarm-sensor.jpg' alt='Laser Range Finder Serial Output' title='Laser Range Finder Serial Output' />For Example, the Display shows 1. Inserting the values in upper formula, youll get a distance about 8. Step 3 Step 3 ProblemsAccuracy. Step 3 ProblemsAccuracy. Font That Looks Like Handwriting Microsoft Word on this page. The use of a 3. 0MHz crystal does not allow creating a very precise time base. The aftermath will be an error on the distance about 5m. Increasing the frequency of the time base will improve the accuracy The higher frequency, the more precision. Although there are several crystals available on the market with frequencies up to 1. MHz 5th harmonic, the actual limit is the maximum clock frequency input of the 7. HC4. 51. 0 counters with 5. MHz. Farnell offers counters up to 1. Laser Range Finder Serial Output' title='Laser Range Finder Serial Output' />MHz, but they are expensive, only available for companies and come in boxes with hundreds of it. Another problem is that free frequency bands 4. MHz in Europe can be used by any other equipment like walkie talkies. This means the device will not work, because the receivers will get some other signal that is in the air. The picture shows on the left side the distance measured by out device. The real distance is plotted on the ground. To prevent errors, several measurements had been performed. The fist one is shown by the blue line, the second by the red one an the real distance is located by the orange one. Step 4 Step 4 Parts. Step 4 Parts. Semiconductor 5x 7. HC4. 51. 05x 7. 4HC4. HC4. 04. 01x 4. 09. L0. 51x BD1. 75. 1x BC5. N4. 14. 81x LED red small. Resistor All resistors are 1 metal film, unless otherwise specified. R1x 1k. 1x 2,2k. 1x 8,2k. M1x 1. 0MCapacitor 2x 2,7p. F1x 4. 70p. F5x 1. F4x 1. 00n. F1x 0,2. F2x 4. 70F2x 1. 00FMisc 1x 3. MHz crystal. 1x Transmitter module 4. MHz. 1x Transmitter module 8. MHz. 1x Receiver module 4. MHz. 1x Receiver module 8. MHz. 1x Push Button to start the measurement1x Momentary Switch to reset the clock watch1x small switch to choose between permanent or temporary displayStep 5 Step 5 Schematic. Step 5 Schematic. We thought about uploading layouts for making a PCB, but it its not worth it, because the pin connections and alignment of transmitterreceiver modules are always different. We got very exotic ones from a company in Italy, produced in Taiwan D If you decide to buy one with a high probability they wouldnt fit in our PCB. Step 6 Step 6 Trilateration. Step 6 Trilateration. Suppose you built such a unit, you may ask yourself if distance measurement only is a bit boring. Good news If you built three of these, you can use them for trilateration. Trilateration. Because a radiowave spreads spherically, at 3 given distances a point can be clearly defined A circle is simply the set of all points infinite with the same distance to a point. The intersection of two spheres is a circle. The intersection of three spheres is one point. This can be used tracking an object for example a car GPS uses exactly the same principle. Step 7 Step 6 Conclusion. Step 6 Conclusion. This new technique of measuring distances is a great alternative to conventional laser methods. But the largest advantage is that you can measure through whole buildings. And the way it is built up is also simple enough to push this project easily forward with minimal knowledge of electronic. And you can use it without any knowledge of measurement technics. To sum it up Its easy to use, its easy to built, its cheap and its a new revolutionary method of distance measurement.