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There is a simple algorithm on Wikipedia: how to build ultrasound image. And I want to build one. Resolution and presision are of no importance, I just want to do this for the case of study - I want to make such an "image 1D+depth slice" of a 20m^2 room. So I may just use these low frequency sensors - 1cm is enough.

So, as stated in the article, I need a phased array (to direct wave). And accidentally I have a couple of Arduino sensors HC-SR04:

enter image description here

Everyone uses them, but I stumbled how to use them. Interface seems to be totally weird, insuffient and unusable. Despite there are (visually) so many logic ICs soldered on the back.. So why is it designed so poorly and how to fix that?

Could you help me - where and what would you solder/desolder to use it for ultrasound imaging? I think that sensors itself could suit for this task.

PS. Basically I need to measure echoes delay (for depth) and echoes streight (for pixel brightness)

It should work on the phased array principles, without rotating, moving, without using any motors. Desired radiation pattern is illustrated by following animations: enter image description here enter image description here

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  • Is it even possible to draw a 2D image with this sensor? There is just one receiver so the triangulation of the source of the echo is impossible. The algorithm description in Wikipedia looks more like "How to draw an owl" meme. knowyourmeme.com/photos/572078-how-to-draw-an-owl In reality this task is very complicated. Technically You can use this sensor with 2 steppers to draw image pixel-by-pixel but it will take minutes. – Filip Franik Mar 29 '19 at 13:41
  • @FilipFranik As it was stated: "And accidentally I have a couple of Arduino sensors HC-SR04".. So its possible. Also, sorry, I dont learn memes (head space is way limited to trash it with remembering useless memes). – xakepp35 Mar 29 '19 at 13:44
  • What I meant was "the description of algorithm in Wikipedia is misleadingly simple, whereas in reality the task is not". Having couple of those sensors helps, but you will need a device that sends only a single pulse of sound and then several microphones listen to the result (those sensors can't do that), then the tricky part comes, you need to look for local minimums and maximums in the result trying to match them between sensors. This way you can triangulate (in 3D) what pixels should be brighter. This is a very interesting (and difficult) project, and I will think more about it. – Filip Franik Mar 29 '19 at 13:53
  • @FilipFranik My PC sound card (EMU1212) has 2 Output and 2 Input channels; It can easily sample at 192khz, meaning that generating/recording square wave at 48khz frequency is a simple task, as well as aligning/analysing phase (in software) - just shift signal start in left or right channel.. And 2 SR sensors has exactly 2 transmitters and 2 recievers (to be desoldered from such a poorly designed sensors). But also they have some logic, I wondered can I reuse a part of it? – xakepp35 Mar 29 '19 at 13:56
  • The datasheet for the sensor doesn't say what chips are located on it. Could you please write the numbers you see on them in the question?. According to here osoyoo.com/2018/08/… they are two LM324 (quad op-amps) and MAX3232 (RS323 transceiver) This would explain the strange interface since this looks like a clever hack to lower cost of the sensor. – Filip Franik Mar 29 '19 at 14:16

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