💬 Distance Sensor

[ben999]

@jjk sensor head need to be perpendicular to surface being measured?

[zboblamont]

@jjk If the readings you ARE getting are accurate when moved to new positions, it could as @ben999 said be inaccurate alignment to the reflective surface, or as was commented somewhere else, the plug/socket on the board being loose.
With a 3/4 to 1/2 reducer on a 1/2 pipe ready here for final installation, I sat transducer the socket to take out movement or alignment issues, it drifts off quite readily if angle is wrong. The code Ben refers to for this DYP gave me a slightly lower but not silly first reading then consistent results thereafter, no zeroes.

Please note that I had tried all 6 sketch variants on the 3.3v device with a 5v DYP supply and got nonsense. Using the 3.3v Trig with drop resistors on the Echo neither the JSN nor the DYP worked properly despite the 5v power from the separate booster supply to them.
I only found consistency using a 5v pro-mini, with the DYP power supplied from logic pins, which leads me to think Trig and/or Echo are also 5v sensitive, contradicting previous advice and complicating my layout.

Have not yet got round to trialling a logic converter from the 3.3v pro-mini for Trig and Echo with the original 5v supply, which is the next step, will report back once I get some time to test.

[jjk]

@ben999 and @zboblamont thanks for the swift feedback and advice. I think you are right, the DYP seems to be VERY sensitive to alignment. The tests I did were "handheld" and readings jumped arbitrarily btw zeroes, accurate, and off values. I've done a few tests now with the sensor head fixed and more aligned to the target surface and that seems to work out much better now. I also found that readings get less accurate above 1m, though?!

[jjk]

btw. I'm using a pro mini 5V to power and trigger the DYP at the moment. Have played with an external 5V supply, but that didn't seem to make a noticeable difference.

[zboblamont]

@jjk Sounds like you're getting there, it should be no problem with the 5v pro-mini, the only variables should be alignment and sketches.

To clarify, I only got a 5v pro-mini to figure out whether the DYP and JSN devices would work, which they did after trying different sketches. Those same sketches had retrieved garbage on the 3.3v pro-mini, despite a separate 5v supply to the DYP, running contrary to experience of others. That supply was unnecessary with the 5v pro-mini.

As the 3.3v is the intended battery powered radio node, I need the DYP to work with it, hence the logic level converter being the next attempt to get the DYP to work with the node.

[ben999]

DYP measuring range starts at 30cm -ish

When water tank is full-up, water level is near the top of the cistern...

So to achieve the minimum reading distance I used a big PVC pipe placed vertically on top of cistern (about 30cm) through a hole...
I went from 5cm to 8cm but no luck : I guess there must be some "echo" in the pipe that fools the reading...

I will end-up with a plastic bucket (dia 30cm height 30cm) on top of cistern opening (not tested yet)

Final word : be aware of confined spaces, that sensor is kind of claustrophobic ;)

[ben999]

I don't quite like the idea of the DYP board being powered full-time...
It "ticks" every one second and i only need a few updates of water level per day.

I would like to power it via a transistor (itself being triggered by arduino)

What would be your thoughts on that ?

• powering that board say 4 times a day for 10 seconds would be more deadly than being powered on all the time ?
• looks like the serial "conversation" kicks-in as soon as power is applied to the board... could it damage either board if serial link is cut anytime ?
• DYP board uses on average less than 15mA. What transistor would be a good contender for that job ?

Thanks again for reading and thanks even more for your input :)

[zboblamont]

@ben999 Surprised if you are getting echoes in a pipe, there are no surfaces to reflect the signal. Both the tanks I am looking to monitor are quite big, I might have to use a pipe in the water tank as it is a plastic moulding which has vertical facing flats on the ribs. Will report back once tested in place.

I looked at transistor switching the device due to RTC and radio occupying all but 4 analogue lines on the node, but there were reportedly some issues with switching ground, so I settled on the latching dpdt relay I posted further up the thread. It needs two pins to open or close by changing outputs from high to low. It opened or closed in less than 30ms, about 33mA from memory, zero consumption once latched.

In my own case the node is 3.3v, the 5v boosted line for the DYP power was originally controlled by the relay.
Having established now that the DYP requires a 5v trig/echo, the relay is being reworked so one contact switches the 3.3v the other the 5v to power both the DYP and the level switcher, hopefully resolving earlier failures.

[Newzwaver]

Hi Everyone,

Just trying to get everything set back up correctly and I def have something wrong, my distance sensors show Zero.
0 MCO:BGN:INIT NODE,CP=RNNNA--,VER=2.1.1
3 TSM:INIT
4 TSF:WUR:MS=0
11 TSM:INIT:TSP OK
13 TSF:SID:OK,ID=254
15 TSM:FPAR
51 TSF:MSG:SEND,254-254-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
2059 !TSM:FPAR:NO REPLY
2061 TSM:FPAR
2097 TSF:MSG:SEND,254-254-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
2615 TSF:MSG:READ,0-0-254,s=255,c=3,t=8,pt=1,l=1,sg=0:0
2620 TSF:MSG:FPAR OK,ID=0,D=1
4105 TSM:FPAR:OK
4106 TSM:ID
4107 TSM:ID:OK
4109 TSM:UPL
4118 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
4128 TSF:MSG:READ,0-0-254,s=255,c=3,t=25,pt=1,l=1,sg=0:1
4133 TSF:MSG:PONG RECV,HP=1
4136 TSM:UPL:OK
4137 TSM:READY:ID=254,PAR=0,DIS=1
4150 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0100
4157 TSF:MSG:READ,0-0-254,s=255,c=3,t=15,pt=6,l=2,sg=0:0100
4166 TSF:MSG:SEND,254-254-0-0,s=255,c=0,t=17,pt=0,l=5,sg=0,ft=0,st=OK:2.1.1
4177 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=6,pt=1,l=1,sg=0,ft=0,st=OK:0
4211 TSF:MSG:READ,0-0-254,s=255,c=3,t=6,pt=0,l=1,sg=0:M
4234 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=11,pt=0,l=15,sg=0,ft=0,st=OK:Distance Sensor
4246 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=12,pt=0,l=3,sg=0,ft=0,st=OK:1.0
4265 TSF:MSG:SEND,254-254-0-0,s=1,c=0,t=15,pt=0,l=0,sg=0,ft=0,st=OK:
4272 MCO:REG:REQ
4282 TSF:MSG:SEND,254-254-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
4289 TSF:MSG:READ,0-0-254,s=255,c=3,t=27,pt=1,l=1,sg=0:1
4294 MCO:PIM:NODE REG=1
4296 MCO:BGN:STP
4298 MCO:BGN:INIT OK,TSP=1
Ping: 0 cm
4336 MCO:SLP:MS=5000,SMS=0,I1=255,M1=255,I2=255,M2=255
4341 MCO:SLP:TPD
4343 MCO:SLP:WUP=-1
Ping: 0 cm
4380 MCO:SLP:MS=5000,SMS=0,I1=255,M1=255,I2=255,M2=255
4386 MCO:SLP:TPD
4387 MCO:SLP:WUP=-1
Ping: 0 cm
4425 MCO:SLP:MS=5000,SMS=0,I1=255,M1=255,I2=255,M2=255
4430 MCO:SLP:TPD

Any idea why? Pins are set correctly 5 and 6.

Thanks

[ben999]

@Newzwaver which sensor are you using? And which library?

[Newzwaver]

Thanks for the reply, I am using the HC SR04

[zboblamont]

@ben999 Finally good news at least on getting the DYP-SR04T-2.0 to behave with the 3.3v Pro Mini, currently arrangement like wire spaghetti. How it all fits in the weatherproof box is another day's work, as is coding it up to send hourly data back to the Gateway.

Earlier trials using the 5v Mini worked perfectly, so ended up with latching relay and booster on separate battery pack, unfortunately I did not realise the complications of using a single coil latching relay on the Arduino.

Needed to get some work done on the house, so delayed getting back to until last week.

So the working hardware is now 10k resistor to DIODES DMG6968U-7 switching a NEC EE2-3TNU double coil relay, a level converter for trig/echo, and a 5v booster to power the ultrasonic. Works fine now even though the first reading is still always a Zero.
Relay switch on and switch off is less than 10ms- Arduino and low current..

[zboblamont]

@ben999 As a postscript to the above, I puzzled over how quickly I could get a valid result before being able to power down the secondary circuit of relay, booster, level converter etc...

I looked at the results coming in (in this case from the JSN sensor) and read up on median analysis and gave up pretty quickly on that level of sophistication, as I realised only the first result was incorrect, that puzzling zero, all the rest were consistent and repetitive.

Inserting a while statement in the Void Setup (instead of the forever version in the Void Loop) checking the time duration < 1, I got a valid result immediately after the first ping, and the secondary circuit could be shut down.

As I only need one valid result to switch the relay off and radio the reading in once and hour, this seems to satisfy my requirements while limiting power drain on the secondary circuit.

[peerv]

I had to add some lines to the sample sketch to get console printouts:

#include <SoftwareSerial.h>

and in the void setup():
Serial.begin(115200);

Is everybody so specialized that they see immediately this omission? :-)

[mfalkvidd]

@peerv strange. Those lines should not be needed. I've never had to add them.

What board are you using? Did you change anything in the example sketch?

[peerv]

I am using a Nano V3.
Apart from the above lines I didn't change anything in the sketch.
Before the change I only got debug messages and no Serial.print lines!

Is the SoftwareSerial.h included in one of the other libraries?

[mfalkvidd]

@peerv SoftwareSerial should not be needed at all, the hardware serial is used.

[peerv]

Thanks. Due to some bad dupont cable connection the program was not entering the void loop() and not printing to the console. Was not aware about a hardware serial print. It is stable now.

[peerv]

Found a new distance sensor HC-SR04P .
De spec shows that the input voltage of this model is 3-5V. So this model can be used with a 3.3V arduino.
https://www.aliexpress.com/snapshot/0.html?spm=a2g0s.9042647.6.2.1AslKf&orderId=89862296499774&productId=32711959780

[Ritesh T]

Sorry for bumping up an old question but I’m in the same boat of requirement.

And to my surprise there are quite a few new sensors in town:

This one has 2 transducers instead of 1 therefore has less minimum detection distance as compared to JSN SR04T. It is also completely sealed and waterproof.

Ebay spam link removed by moderator

Before finalizing on this I had bought another one which was a waterproof modified version of HC-SR04 from here

Ebay spam link removed by moderator

The 1st one is much more rugged and waterproof as compared to the latter one