JSN-SR04T alternative

im using a JSN-SR04T sonar sensor to detect water level. come to find out this thing has a 1 ft blind spot... practically makes it useless to me. is there anything i can do to shorten up the blind spot? is there another waterproof sonar sensor i can use that dont have such a large blind spot?

Got a link?
Got code?
Schematic?

AWOL:
Got a link?
Got code?
Schematic?

well i bought the sensor here USA Ultrasonic Module Distance Measuring Transducer Sensor Perfect Waterproof | eBay and when i bought it i didnt realize it said it has a 25cm blindspot. which makes sence because i can make it accurate but only if its at least a foot away from what im measuring. these code is a little jacked up because i dont really understand whats going on but it should give you an idea. also the only way i could get this sensor to work is if i put a 10kohm pulldown resistor on the trigger pin.

unsigned long WaterWait = 15000;
unsigned long Waterdelay = 0;
int trig = 12;                 //Water Level Sensor
int echo = 11;
unsigned long t;
unsigned long h;
unsigned long hp; 

unsigned long t = 0, h = 0, hp = 0;
  digitalWrite(trig, HIGH);
 if (millis() - Waterdelay > WaterWait) {
  digitalWrite(trig, LOW);
  t = pulseIn(echo, HIGH);
  h = t / 100;
  h = h - 5;      // offset correction
  h = 55 - h;    // water height, 0 - 50 cm
  hp = 3.7 * h;  // distance in %, 0-100 %
 
  Waterdelay = millis();
  Serial.print(F("The Water Level Is At "));
  Serial.print(hp);
  Serial.println(F("%"));

also when the water level im measuring is at 100% it will be about 2 inches below the sensor. the hc sr04 worked perfect for a couple of days until it got wet

That code is incomplete.
But you knew that.

Are your shift keys broken?

AWOL:
That code is incomplete.
But you knew that.

yea i know. but what are my options now. can i change the transducer on the board?

notsolowki:
yea i know. but what are my options now. can i change the transducer on the board?

Yes. Of course.
What did you have in mind?
What do you think it will achieve?

AWOL:
Yes. Of course.
What did you have in mind?
What do you think it will achieve?

well the water level i need to measure is about 2ft. at 100% water level the water would end up being about 2 inches below the sensor. i need to measure it from 100% to 0% accuracy is not really important as long as its near. the tank that the water is in is about 4ft by 4ft x 2ft tall. not sure what i have in mind do you have any ideas?

Think about it.
You kick the the transducer really hard because you want a lot of power in the outgoing pulse.
Then you have to wait for all the mechanical ringing to die away (it's a strongly resonant device remember), because you're going to have to listen really hard for the return using the same transducer but you don't want to hear any ringing. So, you wait a long time.

AWOL:
Think about it.
You kick the the transducer really hard because you want a lot of power in the outgoing pulse.
Then you have to wait for all the mechanical ringing to die away (it's a strongly resonant device remember), because you're going to have to listen really hard for the return using the same transducer but you don't want to hear any ringing. So, you wait a long time.

you lost me, are you talking about the code? i can get the reading to work if its at least a ft away. but please educate me because all the sensors i see on ebay all have 25cm blind spots. also as you can tell from reading what im saying i dont really know anything about sonar except the basic concept on how it works. are you telling me to turn down the power to the transducer and i can get it closer to what im measuring with a more accurate reading?

No, I'm not talking about the code because I haven't seen it.
I'm talking about the limitations of badly-implemented parking sensor sonars.
( One foot is 30 .48cm, not 25cm)

AWOL:
No, I'm not talking about the code because I haven't seen it.
I'm talking about the limitations of badly-implemented parking sensor sonars.
( One foot is 30 .48cm, not 25cm)

Well you sound very educated in the subject. what would you recommend? as in what would you do if faced with this task. would you use sonar or some other kind of sensor? the water is non pressurized 70f water with quite a bit of minerals in it

I have no idea, because I don't know what the limitations of your installation and budget are.

AWOL:
I have no idea, because I don't know what the limitations of your installation and budget are.

how about, under $100. for sake of simplicity lets just assume we are measuring the water level of a small 200 gallon 4x4x2 swimming pool. keeping in mind that there is already a sensor thats grounded to the arduino a "pH" sensor in the pool. specs of the water are , lots of minerals , room temperature. and not looking for scientific accuracy

Why don’t you just raise the sensor by 30 cm, so then the “blind spot” won’t matter?

well the then problem becomes it will be reflecting off the lid. maybe a swimming pool was a bad example. i just read that the HC-SR04 is capable of measuring 2-500cm which explains why it workd good until it got wet. is there a way to waterproof this sensors transducers. the way i was using the old HC-SR04 i drilled 2 small hole in the lid and just pushed the transducers through but water droplets for on the lid which resulted in a soaked transducer. there would never be any turbulent water aimed at the sensor ever it just gets wet from evaporation condensation

in your previous message were you hinting i could maybe make use of 2 of the same transducer to be able to receive the return faster due to not waitng for the ring to go away.

I'd be inclined to use a HC-SR04, but replace the transducers with parking sensor transducers.

AWOL:
I'd be inclined to use a HC-SR04, but replace the transducers with parking sensor transducers.

would this solve my range issue. using 2 transducers 1 for trigger 1 for return?

I really don’t know.
I’d buy a cheap SR04 clone and a set of car sensors, unsolder the Murata (?) transducers from the SR04 and solder in the car sensors in their place.

I bought a waterproof sensor few days ago, which has 2 transducers instead of 1 and therefore has a much smaller blind distance: Sealed Waterproof ultrasonic/distance small blind sensor arduino Fully Genuine | eBay