Thank you for your answer. Seems like there is a wide range of frequency and voltage requirements. I found some PDF files that you left here, but they seem to be old ones that you changed already. The ultrasonic pulses collide an object and leaves in the other direction. It’s the kind of thing cars uses for their parking aids, telling you if there is an obstacle and at what distance. By the way: Click here for an overview over the ultrasonic anemometer project: https://soldernerd.com/arduino-ultrasonic-anemometer/. An ultrasonic anemometer on the other hand sends and receives ultrasonic pulses and measures the time-of-flight. So maybe it’s just the physical design of my prototype that poses too much resistance to the wind and therefore causing too much of a dead wind effect. Signal frequency is 40kHz so one full wave corresponds to 25us. The legs put it at the right height for the anemometer prototype. I am not so good at electronics (access to a shield would be great) but I can definitely help with hard testing (sailing) and programming. Theo This type of sensor emits a burst of ultrasonic sound and then waits to hear the echo. Please help me. To get the windspeed a bit higher a nozzle is needed. I would have guessed the wind speed in the tunnel to be quite a bit higher than 5.3m/s. Arduino's pins can generate a 10-microsecond pulse and measure the pulse duration. This is my second replay because I wrote the arduino forum and carl47 till latest comment. Connect the +5V pin to +5v on your Arduino board. I want to be able to measure both wind speed and wind direction with high accuracy. These blind … I went back and checked my code but didn’t find any bugs there. Couple questions: 1) would a Tl852/TL851 sonar ranger IC provide any value in this application? The other day, I was discussing an IoT project with a talented student group. Add a second pair of senders and receivers at a 90-degree angle and you get both wind speed and direction. The ultrasonic sensor sends 8 pulses of 40KHz via the trig terminals (inaudible to humans, it's ultrasounds). The Ultrasonic sensor has four terminals - +5V, Trigger, Echo, and GND connected as follows − 1. There are two holes at the bottom through which the anemometer’s arms can be inserted. It’s powered by a powerful 120mm size brushless fan drawing some 2.25 amps at 12 volts. Turns out that you really need to get the flow somewhat laminar. -On the analog board I had to change some component values to get the desired gain. Hi Martino. In a 2-dimensional anemometer such as here, you will have 2 pairs of transducers for a total of 4. For my very first tests I had misappropriated my wife’s hair dryer to generate some wind. If you wonder who or what Jingling Ding is: That’s the name of my step daughter who helped me drawing and laying out this PCB in Eagle. We were running through a bunch of sensors that they can use in their project. Yes, speed of sound varied considerably with temperature and this needs to be compensated for. => c=r/2(1/t_plus+1/t_minus) and v=r/2(1/t_plus-1/t_minus). You are correct, if you consider only one axis, you have two equations with two unknowns – perfect. All of his documentation can be found here: https://mysudoku.googlecode.com/files/UltrasonicAnemometer.zip. Have you got any schematics that I could have a look at? Maxim. An ultrasonic sensor is used to measure the distance to an object using sound waves. That’s what’s shown on the photo at the top of this page. So let’s learn about Distance Measurement Using Arduino & HC-SR04 Ultrasonic Sensor. But I didn’t look up the data sheet and at 4.84m^3/s your calculations are of course correct. Click here for an overview over this series of posts on the anemometer project: https://soldernerd.com/arduino-ultrasonic-anemometer/. Thank you for your comment and especially your willingness to contribute to this project. Tell me if i can help you by testing prototypes at the wind tunel or trying to get the wind calculation algorithms working properly. They cost around USD 5 in small quantities. Each sensor is capable to transmit and receive ultrasonic pulses. Saludos desde Argentina!!! If you do two measurements of time-of-flight, one in forward direction and one in backward direction, you get t_plus = r/(c+v) and t_minus = r/(c-v) with distance r, speed of sound c and windspeed v. Now you have two equations for two unknowns. The calculation is based on constant rpm of the fan. 2. You will then need some more circuitry to process the received signal. Downloads. For me it’s difficult to really test the anemometer because I never know what the true wind speed is, even approximately…. Lukas. Just read the “about me” section. I did end up changing quite a few things and will explain my reasons for doing so but the general approach is very much the same. That’s just a fancy name for a wind meter. And starting with a larger intake area, with flow straighteners (e.g., straws) and a smooth taper down to the smaller cross-sectional area will give you a more laminar flow. The version2 from Carl he mentioned, this one is not working either. Therefore, we can get the distance from the ultrasonic sensor by using two Arduino's pins: 1. This build and its previous iterations have been years in the making, and you can check out the full timeline of development here on his blog . Here’s the circuit I built using a 4-wire jumper harness to wire the ultrasonic sensor to the Arduino. Also. The mods you made are these done on the version 2 from Carl? Probably doable but not straight forward to do in a 8bit microcontroller. The HC-SR04 Ultrasonic Module has 4 pins, Ground, VCC, Trig and Echo. I’m also a hobbyist with no formal education at all the subjects i explore to work and to get fun! Many thanks for sharing this with us, Carl. Maybe some of you have a piece of advise for me…. No, compared with the mechanical principle, the price of the ultrasonic anemometer is higher, but if considering from the comprehensive cost, its performance-price ratio is the highest. I built an anemometer based on measuring dynamic pressure. Wow! But this is quite easy to do by just measuring the temperature (there is a temperature sensor on the shield) and doing the math with the adjusted speed of sound. Working principle of ultrasonic wind sensor. Seems like some of these US transducers are power hogs and put out a really weak signal. https://soldernerd.com/arduino-ultrasonic-anemometer/, https://en.wikipedia.org/wiki/Volumetric_flow_rate, http://navier.stanford.edu/bradshaw/tunnel/LowSpeedTunnels.pdf, http://www.lcjcapteurs.com/product/cv7sf/, http://www.utdallas.edu/~taylor.barton/CPIRSE2012_windsensor.pdf, Arduino Ultrasonic Anemometer Part 4: Testing the analog board, Ultrasonic Anemometer Part 29: Transducer Comparison, Ultrasonic Anemometer Part 16: Testing the new driver circuit. It’s great to know that there are people with access to wind tunnels. So little to be completed!! Connect GND with GND on Arduino. You need to be able to send and receive pulses in all 4 directions: N->S, S->N, E->W and W->E. Not all at the same time but one after the other. It provides measurements of the time that takes the sound to fling something and return it to the sensor. I have done some more testing and will follow up on this shortly. Ultrasonic Wind Sensor Aluminium Construction, Optional Heating System Vibration BS EN 60945 : 2002 Precipitation 300mm/hr **** 2-wire is point to point only Pipe Mounting (optional) 44.45mm (1.75 in) diameter Wind Software Display / Logging** Cables (optional) Available to match output options Display (optional) See Gill Display datasheet If this all sounds interesting, you can try it out yourself very easily using an Arduino and an HC-SR04 sensor. Because I have version 1 from Carl and I would like to give it unother try to get the system working. I’ll post the results I got at maximum fan speed shortly. In this tutorial, we learn how to measure the distance by using the Ultrasonic Sensor with Arduino. or is it necessary to use driver IC for some other reason? The transducers are then nicely centered inside the cardboard tube. The wind tunnel is not of that much use the way it is now…. Greetings from Sweden! I hope to follow up on this project in a few weeks time when I’m settled in my new home…. Basically, there is this one brave guy named Carl who has built such an anemometer from scratch and put all the relevant infomation online.His project was published on hackaday.com and this is where I found it: http://hackaday.com/2013/08/21/ultrasonic-anemometer-for-an-absurdly-accurate-weather-station/. Required fields are marked *. Hi, This proyect would let us improve our realibility in wind measurements for our wind map of the region. The standard way to calibrate/measure air flow in a wind tunnel is using a differential pressure sensor on an L-shaped pitot tube. WindSonic75 is a compact, low-cost 2-axis ultrasonic anemometer, providing high wind speed (0-75m/s) and direction data in a robust housing. Pressure (Pa) = 1/2 (rho) *U^2, where rho is the air density (kg/m^3) and U is the wind speed (m/s). The received signal is analog in nature and will be very weak compared to the transmitted one. lukas, Your email address will not be published. i believe it works but in what way? Compatible with the modules HC-SR04, Ping))) and Seeed Studio sensor. I need this file”https://mysudoku.googlecode.com/files/UltrasonicAnemometer.zip.” Learn how your comment data is processed. Another pin is connected to ECHO PIN measure pulse from the sensor Make the channel larger and add cones to intake and exit. In my next post I will go through the details of the two circuits. Let me quickly outline the project: My aim is to build an ultrasonic anemometer based on a Arduino Uno board. https://soldernerd.com/arduino-ultrasonic-anemometer, http://hackaday.com/2013/08/21/ultrasonic-anemometer-for-an-absurdly-accurate-weather-station/. Lukas, What makes this difficult is that I don’t know the true wind speed so maybe the wind is just not as strong as I think it is. I’ve used Carl’s project report (that 31 pages PDF file named ProjectReport.pdf from the zip file that I have linked above) as my starting point. Ultrasonic Anemometer ‘Up and Running’ – Measures Wind Speed & Direction Congrats to Lukas ‘soldernerd’ Fässler for the latest developments in his ultrasonic anemometer project. Most wind meters are of the cup or vane variety. I could well imagine building a few of these shields and send them to people able and willing to help its further development. Let’s call it the digital part even though the received signal is analog in nature. Of course the results wereneither reliable nor repeatable so I built myself this ghetto wind tunnel: It’s basically a 120x120mm square tube, made of cardboard and about 1.4m in lenght.