Need Help to Designing an Arduino-Based Ultrasonic Doppler Sensor Using MA40S4R/S

Projects General Guidance
1

Hello,

We are high school students conducting physics R&E.

We are conducting R&E on ultrasonic Doppler sensors.

I'm not good at English.

We are trying to build an Arduino-based ultrasonic Doppler sensor,
and implement ultrasonic transmission and reception using the MA40S4R and MA40S4S.
Some members of our team have worked on various projects using Arduino.
We also have an Arduino DUE and an Arduino UNO, and we have the LM358P, TC4427COA, and CD74HC4016E. Searching has shown that various amplifier circuits are needed to utilize these, but we haven't been able to find a solution. We also don't understand Arduino circuitry.

Therefore, we'd like to know about solutions or alternative solutions.

We previously performed ultrasonic analysis using the HC-SR04 and an oscilloscope, but this didn't seem suitable for the sensor.

2

Looks like you copied it off a PDF.

A 40kHz "signal" has a 40ms period, and can be a square wave...

unsigned long dTimer, dTimeout = 40;
void setup() {
  Serial.begin(1115200);
  pinMode(LED_BUILTIN, OUTPUT);
}
void loop() {
  if (millis() - dTimer > dTimeout) { // compare "now" to timeout variable
    dTimer = millis(); // reset timer
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
  }
}

How is this "urgent?"

Not me.

1 Like
3

OP, did you look at the preview/draft before pressing ‘SEND’ ?

Please read the guide to posting at the top of each forum category.

2 Likes
4

Did your google die?

Problem is this:
You, as a beginner, send a prompt to Gemini.
This prompt is ambiguous and incomplete...
Instead of asking for more info, Gemini wants to be your friend. It gives you a hug, fills in the gaps, steps over ambiguities, starts looking in its database for things that might fit parts of your question, mangles that together and presents you a convincing story.
And now, we can do the real work... derive the things you asked to gemini from its output. Ask you to fill the gaps and resolve ambiguities. Solve the problem. Present it to you...
Please, in your own words, describe what you want... Then we can give directions. And for a start, I am sure google can find an amplifier circuit around your opamp LMxxx. You might also find it in the datasheet for the opamp (usually at the end where the examples are). Show your effort.
And have a look at your text (it does not render nicely, since it is not in .md format).

2 Likes
5

I'm not good at English.. I don't know how to configure Arduino circuit..

6

This is the first time I have seen this "R&E" "Research And Engineering" Taking the "R" portion of that and applying it to my DuckDuckGo search engine looking for "analog application manual" I found many including Op Amp design etc. Rather then post a link since this is to teach Research I highly you suggest to exorcise part of what you are learning and use a search engine. I believe there is some information in the Arduino cookbook as well.

7

I'm korean and in our country R&E is Research and Education. We don't have that level of skill.

8

North or South?

1 Like
9

Just out of interest, why are you looking at Doppler sensors?

I've only come across them twice in different applications, both flow related.

One as flow sensors in pipework (water treatment), the other recently in blood flow in a circulation scan. Ultrasonic Doppler device on both ankles to check for normal blood flow.

Blood flows in one direction as the heart beats, then a small reverse flow, followed by a smaller forward flow. That's triphasic flow. Age can progress it to biphasic flow, and in worse cases, there are no reverse flows, a sign of vascular problems.

10

Perhaps you need to start on the transmitter side rather than the receiver side of the project. Are you able to create the 40kHz, up to 20 volt peak to peak signal to drive the sender unit?

11

Sounds like you are re-inventing the HC-SR04. You can easily find component-level schematic diagrams on-line.

You were taught about the subject you are studying. Use classroom information, and add some team members' knowledge. That is what teams do.

Your language skills are good. Use Google Translate if you need.

1 Like
12

Might be a good beginning, but the OP is needing to work in the frequency difference domain, while the HC-SR04 operates in the time difference domain, which is so much easier to do. Perhaps the OP does not really understand Doppler circuitry and code.

13

What is the point of this research?

14

1000ms / 40960Hz < 1ms period.

40ms period is 25Hz. 1000/25 = 40.

15

I messed up t = 1/f

1 Like
16

Please describe the Doppler effect you are going to use and how you will program for it. I doubt you really know what it is.

1 Like
17

I trained to use a 1968 doppler radar as part of my MOS… a good while ago. That requires analog circuits that make digital look fall-over easy. It does make frequency differences easy to find but I won’t say how (clearances don’t expire till late 2028).

You can fake doppler with an ultrasonic sensor, as Pul sez, so much easier to do. What limits the number of reads per second will be send and return time. If you get a real radar range finder, that will make the signal travel almost nothing (300m/microsec).

Don’t think that a microwave oven magnetron will let you have radar except in the very crudest sense, they are “all noise”.

18

And if the radar pulse is chirped, the return can identify the source of the echo. Very cool!

19

Doppler sensors operate non-contact and utilize continuous waves to continuously measure velocity. We have a team member interested in electronics and would like to explore this topic.

20

I experimented with the two-dimensional planar Doppler effect in a circularly rotating source by installing a sound source on a rotating disk. In this process, I used the HC-SR04 receiver and an oscilloscope. I plan to build a sensor using ultrasonic receiver and transmitter sensors. The transmitter sensor (MA40S4S) appears to be operational.