thankyou, Ill check this out.
I'm good with that. So you can't set them back 7", but you can separate them by 7".
Edit: OK, I'm not good with that. You must wait for the transmitter signal to pass the receiver before listening. Separating them by 7" will increase the delay required.
Hi,
When you say "blind zone" you mean the sensor cannot detect an object closer than 20cm.
So you want to be able to detect an object closer to the origin.
Why not have a second ultrasonic unit pointing across the 20cm distance of the first, but have that region outside the 20cm limit of the second.
Are you detecting ultimately just the presence of an object or do you need an exact distance?
Tom... 
Thank you for the idea, Tom.
Yes, I want to detect objects closer than 20 cm. However, with the idea of placing a sensor unit 20 cm further from the initial point, it would indeed resolve the blind zone issue and improve accuracy. Unfortunately, the application I am working on does not allow for a 20 cm offset.
I need exact distance measurements.
Using two sensor modules, such as two JSN-SR04T units (both the module and probe, not just the transducers), is quite confusing for me. I am also unsure how to keep the second unit continuously in RX mode.
Thanks for your help!
Thanks for the response
If you look at the HC-SR04 sensor, there is a distance between the RX and TX probes, but it does not need to be 7 inches. The wavelength is not 7 inches either. I want to use the JSN-SR20-Y1 because the probe installation is easier and suits my current needs. The issue is not with the wavelength or the parallel distance between sensors. A slightly greater parallel distance between sensors will not affect the sensor delay, unless one probe is positioned significantly ahead or behind the other. If the probes are parallel, it generally won’t affect the delay, unless the distance is too great and the signal needs to bounce multiple times before reaching the RX probe.
That part is correct. I did not say wavelength. I said transmitter pulse (several wavelengths)
The wavelength is 8.65mm. The receiver is going to require several wavelengths to set off the output. If the transmitter is still transmitting, you are going to receive that as an echo.
Good luck.
Hi,
What maximum and minimum range do you need?
Tom..
ok my bad, but thats exactly why i said
so that the rest of the echo is not treated as incoming signal
You can't start immediately. If separated by a foot, it will take about a millisecond for the transmitter pulse to clear your receiver before you can start listening, or the receiver will detect the transmitter pulse as an echo, and stop listening.
The DYP-A02YY goes down to 3cm and is pretty stable and precise and the waterproofing is good. Are those attributes you are looking for or you just care about the minimum distance regardless of accuracy?;
(And yes, If you need less than 3cm then get another one that you install a bit further and you get to 0)
Why don't you use an automotive sensor in your project?
It has 4 sensors.
This is the JSN SR04T module board.
Front:
and rear
I reverse engineered it using this image:
and I drew this schematic of it.
The U1 chip maybe a processor, but I don't find number.
I already have this. the DFRobat Version, uses UART, kind of a bad choice
this is really helpfull, but how can you make it into 2 or even 4 probes?
one as transmitter, the other as receiver?
No, this model is for 1 single probe only.
Same as what you posted in #14.
And this is HC-SR04 schematic.
And this is my friend project for 4 sensor.
thank you. this is very helpful.
the 4 sensor part means the other is the transmitter and the other is the receiver or the 4 transmitters and after that, they became the receiver, making it work just the same as JSN SR04T?
who can help me with the code for this sensor
Create your own topic, expose your project and your difficulty.
I am searching for the transformer on the JSN-SR20-Y1... I can't find it anywhere... someone knows what is it? where can I order that one?
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.