xilebali whytlee esther
Florentina Holcombe
I'm new to the world of RF communication and was interested in building a miniature radar unit powered running off an Arduino uno/nano. The radar is only a proof of concept on a small scale so won't run into issues with HAM licensing and the like.
I'm not 100% certain whether an Arduino can natively create a suitable antenna signal pulse, send it with an antenna like a monopole or dipole antenna and then await a response signal, and then based on delay or phase shift determine a target's range or velocity. As some antenna types are considered "dead shorts" in DC and the arduino is natively a DC device, just want some advice before i accidentally blow up my board.
Even if you were really clever and could measure the time of the reflection in machine cycles instead of microseconds you can't do much better.
For a typical Arduino with a 16MHz clock, then you can only measure time in units of 62.5ns, during which time the signal has travelled 18.75m.
There are experienced Arduino users who also have a lot of RF experience and knowledge. You might then expect that if an RF RADAR with an Arduino was possible, then by now someone would have achieved it. Did you find any examples with an Internet search ?
Thanks for the replies, really appreciate the time. I've got a decent amount of experience with arduinos having done some DIY projects for around the house, and also have university experience with RF when I studied physics. But my knowledge based on the hardware limitations of arduino are pretty basic.
Considering the speed of the clock isn't really fast enough to do anything on a small scale, and the power restrictions of the arduino limit its range, it seems that an arduino is not the right method for attempting this. Would it be possible to use arduino to potentially control external hardware to make this possible or would it be more beneficial to just run the external hardware by itself.
Considering that RF signals at least in australia are band restricted and power restrictions apply, you can get around it by not emitting signals into an area where they affect others and are detected for a desk test it is not really an issue
This looks promising, I might look into using something similar. Although wouldn't this potentially also have the same problem where it can detect velocity through Doppler shift but wouldn't be able to determine range due to the sampling time.
Yes, you are right. I wanted to use it for a crude form of distance measuring to detect ground proximity in a model aircraft. But that's just detecting the difference between measuring nothing and measuring some dopplershift when the surface is approaching.
Perhaps more information can help your project.
For radar you need to apply all possible power to hit the target. Any antenna short of a dish type reflector will waste almost all your precious RF power. Also to create a reflected signal you need to send a huge amount of RF power so you can get some power in the reflection! You can research the power loss vs. distance.
You will also need to send the RF power in a VERY short burst so your receiver has time to prepare for the returning echo.
You write of measuring phase shift to compute velocity. Try frequency shift. You also need to be able to process the echo signal to get the frequency shift, which may be only a few Hz.
Relating to an antenna as a DC device. Remember, you are ONLY dealing with RF which is an AC signal. Many antennas are a DC short circuit, which will make no difference to the RF signal. Many of my ham radio antennas are DC shorted.
The antennas on most, of not all modules for the Arduino have capacitors in series with the antennas so DC cannot be shorted through the antenna. Check yours with your Ohmmeter.
The two combine to give a received power that is inversely proportional to the 4th power of the target distance.
That is why you need very high powers to 'see' targets that are a long way off.
OPS241-B Short Range FMCW Radar Sensor The OPS241-B provides a simple FMCW radar sensor solution that can quickly and easily report the range to objects in its field of view. A simple API enables a flexible solution that can be tailored for different...
I started this topic just for curiosity, is it very complex building a weather radar? Im not thinking in a full range weather radar (up to 300km - >3m dish + amplifier), but more a weather radar with range of 40km (used in ships or airplanes) or even less range, 10km.
The doppler unit won't have the range you mention, though it could be used to tell you how fast the tornado is moving, just before it hits you.
Simple doppler won't give you range either.
Always bear in mind the inverse square law.
In this Arduino Tutorial I will show you how you can make this cool looking radar using the Arduino Board and the Processing Development Environment. You can watch the following video or read the written tutorial below for more details.
All you need for this Arduino Project is an Ultrasonic Sensor for detecting the objects, a small hobbyist Servo Motor for rotating the sensor and an Arduino Board for controlling them. You can watch the following video or read the written tutorial below.[/column]Components needed for this Arduino ProjectYou can get these components from any of the sites below:
hi, i want to construct it for my school project. but i just have a week for that. can it be made that easily? in addition to that i have zero knowledge of arduino devices. should i just follow the steps? or is there any more explanation on your site? being honest i m really confused
Great site, great project and thanks for making everyting fun and easy.I just wanted to ask that, is it possible to adapt the code for measuring the speed of an approaching object. I reduced the angle of scanning to 60 degrees and I want to see the speed on the screen if an object is getting closer to the sensor. Any tips to get me started?Thanks in advance.
Thanks. That sounds like a good project idea and you might be able to make it with this or similar sensor and setup. You comparing the distanced the object has approached in a particular period of time.
hi i just want to ask how can i match the distance of the detected object in the sonar since i already change the distance that the sensor to 1m, the distance that the sonar give doesnt match with the distance that the sensor detect
Thanks a ton man!. The project definitely works. The coding is free of error. There is just one slight modification though. The font which you use in the processing IDE needs to be moved into the sketch folder first and you seem to have skipped mentioning that part.
Other than that, this one is an awesome project indeed.
Cheers
Hello and thank you for this project, its really niceI have a problem but beside this all is good
The problem is the servo motor is not rotating smoothly I always have to push it and force it to rotate it does not rotate on itself
Can you help me?
The ultrasonic sensor u used for this project is HC- SR04. I read data sheet of it. range of sensor is upto 400 cm. then why only upto 40 cm can be got by this code. if we consider its measuring efficiency is lesser than ideal one then also it could measure atleast upto 100cm. What changes in code required if i want output of 400cm or 100cm.
hey, i really like this project you have, but I am having, is that for starters the screen for some reason does not fit, but my main problem is that the red lines are not showing up for me when i run the program. everything else is working fine, the green lines are moving and all, but when i place somthing in front of the sensor, no red lines appear. do you know how to fix this? thanks for the help
Are you using the right Processing IDE code, the updated to work on each screen resolution, the one on the bottom of the post. If you are using that one you just have to set your screen resolution and all other drawings will be adjusted according to the set resolution.
Hi,
Really helpful tutorial.
I am experiencing really noisy HC-SR04 data. I was wondering if you have experienced that and if so how did you solve it. Or do you have any advice on what might be the problem.
Hey, great project!!! ?
But I wanted to know how can we make it rotate 360 degrees because the servo can rotate up to 190 degrees. Can we have a wireless radar configuration for making it rotate 360 degrees or a sensor equivalent to 360 radiation pattern?
pls help me out!!!
Thank u
Hi, My daughter is about to do this project with her weekend Science group (all 12 years old).
I just wanted to say that the code and the video and the explanations are excellent, and I think this will be an excellent project for them.I am also going to use it to introduce the concept of Radians to them, as a side note.
Many thanks for your all your efforts and explanations and tutorials. A truly inspirational site.
Hello dejan,
Thank you for the great project!!!
I have a question regarding the display. after clicking the run button in processing, my display only shows partial screen of the scanning radar. Changing the display resolution does not fix the problem. I also change to different font. Please help.
Thanks in advance.
sir i m not getting any output on screen of ide processing it does not show anything
can you please tell do i need anyother java software install in pc???
java.lang.NullPointerException i got this error
sir my processing shows a message could not load font OCRAExtended-30.vlw. make sure that the font has been copied to the data folder of your sketch. what does that mean? im new in this field pls help me
c01484d022