Theremino Ultrasonic Radar

An interesting application developed by Mauro Riboni. Based on an ultrasonic module of type HC-SR04, works surprisingly well and provides a display similar to that of real radar. Here you see a YouTube video:

Unfortunately, ultrasonic modules have very limited features. The maximum distance is a few meters and the radius is 30 degrees wide. But the sensors are suitable for systems that tighten this range a bit (hardware/inputs/sensors # usound).

Although ultrasound technology is only suitable for educational applications or toys, likewise the Theremino Radar application is very interesting. With small changes, you could adapt to the microwave sensors or lasers.

Mechanical construction

One servo for model airplanes directly driven by an ThereminoMaster PIN, wheel the ultrasonic module 180 degrees. The echo signal is connected directly to a second Master PIN. We recommend that you use a low or medium-performance servo. The only request is that it is a model with a range of 180 degrees (hardware/outputs/motors). An ultrasonic module with excellent performance, cheap and readily available on eBay, is the HC-SR04 (hardware/inputs/sensors # usound). Here are prototypes and recommendations from a blog on Robotics: /blogs/robotics and cnc.

Possible developments

The classic microwave radars are workable, but working at distances of tens or hundreds of kilometers, they are then pretty useless for most of us.

What we need instead is to measure distances up to 100 meters, with very high precision. There is a carpenter who is waiting for over 20 a device for measuring walls, ceiling, doors, windows and recesses, all in one fell swoop. They would like to put it in the center of the room by a customer, go and take a coffee, return to recover the data and go home. We were never able to do so, but today we are one step closer (of course you are talking about a small object that must be simple and inexpensive; the ornamental tiles from 1000 dollars we let them do unto others).

Searches for a suitable distance sensor

The only technology that can provide the required accuracy is the laser distance measurement. We will follow this track (see “Micropulse LiDAR”, the chips MAX3086, the PulseLasers by Osram and also this interesting document). We are not the only ones to attempt this road. The best DIY designers are chasing, but for now their best attempts returned 1 or 3 data per second.

These modules are cheap (about 60 Euro) and make up to 100 samples per second. Unfortunately, I have little accuracy (only 5%, not even one-fiftieth of the precision of our ADC). And unfortunately, they do not have an exit immediately usable and will be supplemented with a small PCB with a PIC (but be careful… a small PCB with a PIC from 8 Pin, not an entire Arduino, would be wasted and also huge for this purpose). It is best not to use a “micropulse LiDAR” for analyzing, otherwise the accuracy will always be too poor for what we want to do. I will try again.

Mini Help

• The “Max dist” that you set in the properties of the PIN type “Usund sensor”, in application HAL must match the scale you set in ThereminoRadar.

• The slot 1 is used to move the servo (set your PIN as Servo16)

• The slot 2 is used to read the ultrasonic sensor (set the PIN as “Usound sensor”)

• In the properties of the “Usound sensor” put “Response speed” = 100 and disable “Remove errors”

Release notes Version 1.0 – This is the first version adapted to the Theremino System from the original idea by Mauro Riboni (we thank him for allowing us to use it) Version 1.1 – Small improvements in the resize event of the window and camouflage background. Versions 1.2 and 1.3 – Fixed many small defects were born during the transition from XP to Windows-7/8. Version 1.4 – Delete the flashes on startup.

Download Theremino Radar – Version 1.5 Theremino_Radar_V 1.5 Theremino_Radar_V 1.5 _WithSources For all systems from Windows XP to Windows 10, both 32 which in 64 bit (Linux and OSX with Wine).