Ultrasonic stop working or detecting anything

Other Hardware General Electronics
1

I was working on my dotted PCB where I connected a vibration motor and ultrasonic and arduino nano mainly.
However when I first connected the ultrasoinc to it and welded it I decided to check to see if it's detecting anything from the serial monitor.
It was showing absolutely 0.00 unless I put the pins to a perfect 90 degree angle.
However, when I continued soldering the vibration motor to it and the wires which aer supposed to connect to the battery, I connected the ultrasonic again to check its worling on my laptop and these are what I get
Screen Shot 2024-06-16 at 1.04.39 AM
Basically, I get a bunch of 0.00 and then suddenly a reading and then that reading never appears again no matter how much I turn around the pins.
The following is very bad pictures of my circuit (sorry)

Screen Shot 2024-06-16 at 1.05.53 AM
Screen Shot 2024-06-16 at 1.05.53 AM714Ɨ968 85.9 KB

the blue is a wire connecting to GND and which the GND of the ultrasonic is connected to as well. (not rlly relevant, but just so you are in the picture)
green is the vibration motor
red is the area where the ultrasonic is connected and where (before) I was able to twist to a certain degree and it would work (now it doesnt and is giving me one reading and then the rest 0.00)

I hope anyone can help, I just started on arduino 6 months ago so I would appreciate it
Have a great day

2

Please include a schematic of your project and a good photograph of the underside of your PCB so that the connections are clearly visible.

The fact that you mention that jiggling the wires/pins helps, suggests that there's a contact problem, possibly due to poor soldering. But I may be misinterpreting your description; hence the request for additional illustrations.

3

It used to work when I would jiggle the pins as you said, but no it doesn't help really. Should I try re-soldering it?

image
image734Ɨ980 109 KB

I couldn't take a better picture (sorry)

4

Yes.

solder
solder1920Ɨ2563 357 KB

5

For now, I'd recommend to move your project to a solderless breadboard and get it to work.
Then, or in parallel, practice soldering.

2 Likes
6

I already finished my breadboard.

Screen Shot 2024-06-16 at 6.13.20 PM
Screen Shot 2024-06-16 at 6.13.20 PM1964Ɨ900 133 KB

I made it on tinkercad and in real life as well.
Also what do you mean by the arrows? There are some pins from arduino not here because I didn't need them and there was this black piece that you can add the arduino to, and it was broken frmo the front. (didn't really effect anything just lost some unnecessary pins)

7

Good. Does it work?

Ignore them. I see what you mean; those are pins your project doesn't use. It's OK to leave them like that.
The soldering on the other pins doesn't look very good.

8

Wrong. It is a representation of every solder joint in the picture. Pay very much attention to them and all solder joints.

9

I can repeat the soldering on these parts, but it keeps bridging between the other pins.
I find it hard to make them perfect.

Can you elaborate please, I should repeat the ones connecting to ultrasonic right?

10

Keep practicing. Look at YouTube videos to see how it's suppose to be done.
Use a resin/flux-core solder, the 60/40 kind with lead. Stay away from lead-free solder; it's a b*tch to work with. Use extra flux to make life easier. There's no such thing as too much flux! Try different temperatures on your soldering iron until you find the sweet spot.

11

I actually never used that, I'll give it a try and let you know.

It's crazy how I actually recently changed to it because my old solder finished.

Anyways, thank you I will try re doing it and updating you all.

12

Sure thing; the flux/rosin-core, leaded solder will make things far easier. Please post back on how it works out!

13

... and small spool of "braided copper solder wick" will help you remove excess solder.

Have a look at some more soldering videos. A good video will show plenty of flux, and a "just right" amount of solder "flowed" onto the "just right" heated metal. Through practice, you will know the "just right" amount of solder and heat. You will be pleased with the results.

1 Like
14

Alright, thanks!
I removed all the solder and re-soldered the ultrasonic

image
image526Ɨ700 64.6 KB

this is what I did so far, the 4 pins on the top are the ones that are supposed to connect to ultrasonic. (right Vcc, left GND)
I tried to keep it organised but although I changed the solder iron I used, it keeps getting stuck to the tip of the soldering tool I'm using.

15

Verify with a DMM/continuity tester if (1) the connections you need to make are really there and (2) there are no unintended shorts.

16

I don't really have a DMM continuity tester, not sure if there is anything else I can use.

was this a different point? I didn't understand

17

Get one.

You should verify:
1: That there's good contact/continuity/low resistance between the intended connections
2: There is NO contact/infinite resistance between nodes that should not be connected.

I'm asking because tin omelets like these are always a liability:
image
image

1 Like
18

So I will be purchasing this one (just to check):

image
image600Ɨ600 71.1 KB

image
image600Ɨ600 48.2 KB

these are two different pictures, justto make sure which one

Alright, thank you so much.
I will let you know.

19

Either will be just fine, really. The top one has more measurement features, but the bottom one will get the job done just as well. And the bottom one has a nice touch the hold and backlight features, but I'm sure most of us do just fine without either.

20

Make a continuity tester.

Files for WOKWI.COM tabs

sketch.ino 
// Connect probes to pin 2 and GND
// Connect speaker to pin 3 and GND

#define PROBE_PIN   2
#define SPEAKER_PIN  3
#define LED_BUILTIN 13

void setup() {
  Serial.begin(9600);
  pinMode(PROBE_PIN, INPUT_PULLUP); // probe
  pinMode(SPEAKER_PIN, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  bool probe = digitalRead(PROBE_PIN);
  if (!probe) { // probe has continuity
    delay(150);
    digitalWrite(LED_BUILTIN, HIGH);
    Serial.println("BEEP");
    tone(3, 1660, 50); // pin, Hz, dur
  } else {
    digitalWrite(LED_BUILTIN, LOW);
  }
}
diagram.json 
{
  "version": 1,
  "author": "Anonymous maker",
  "editor": "wokwi",
  "parts": [
    { "type": "wokwi-arduino-nano", "id": "nano", "top": -4.8, "left": -0.5, "attrs": {} },
    {
      "type": "wokwi-pushbutton",
      "id": "btn1",
      "top": -95.9,
      "left": 111.9,
      "rotate": 270,
      "attrs": { "color": "green" }
    },
    {
      "type": "wokwi-buzzer",
      "id": "bz1",
      "top": -112.8,
      "left": 49.8,
      "attrs": { "volume": "0.1" }
    },
    {
      "type": "wokwi-text",
      "id": "legendservo1",
      "top": -86.4,
      "left": 172.8,
      "attrs": { "text": "Probes" }
    },
    {
      "type": "wokwi-text",
      "id": "legendservo2",
      "top": 28.8,
      "left": 124.8,
      "attrs": { "text": "<------\"L\" LED" }
    },
    {
      "type": "wokwi-text",
      "id": "legendservo3",
      "top": -86.4,
      "left": -9.6,
      "attrs": { "text": "Beeper" }
    }
  ],
  "connections": [
    [ "nano:GND.2", "btn1:2.l", "black", [ "v-9.6", "h28.6" ] ],
    [ "nano:2", "btn1:1.l", "green", [ "v-19.2", "h19.2" ] ],
    [ "bz1:2", "nano:3", "green", [ "h-0.4", "v9.6", "h19.2" ] ],
    [ "nano:GND.2", "bz1:1", "black", [ "v-9.6", "h-48" ] ]
  ],
  "dependencies": {}
}
1 Like