HC-SR04+ and wemos d1 mini pro

[Shardan]

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Are this settings for GPIO 12 and 13 are ok, or I must set something?

Just leave them untouched - it's OK.

[Shardan]

I have a 3.3v version. But couldn't get it to work.

Please give some more info.

[NDR008]

I will take photo later.

[NDR008]

This is the one I had purchased:
https://www.ebay.de/itm/Micro-Mini-3-3- ... 2749.l2649

I cannot describe why it did not work well.
I should try again and document my steps.

I hada LoLin NodeMCU working with a contact switch input and I2C BMP-sensor.
Later I added the ultrasonic thingy and things stopped to work, but it may be a result of my non-linear trial and error.
(It was my first time working with ESP, and I was doubting if I had enough power, and all sorts of factors).

[Shardan]

THe nodeMCU's have a voltage regulator 5V -> 3.3V. Usually this is a LM1117-3.3 or an even smaller one.
These regulators can take some current, it should be enough for a HC-SR04.
With the widespread WeMOS D1 Mini it might be near to limits as they use a very small regulator.

Anyways, together with nodeMCU it should work.
Another problem: Powering via USB cable? Try a short and thick cable!
Most cheaper USB cables have wires like a hair... if the HC-SR04 starts sending pulses it might be too much.

Another possible reason:
The US breakout you use is "like HC-SR04" but it obviously uses another circuit inside.
The HC-SR04 has a crystal onboard and another layout, this one has no crystal.
So it is questionable if they are really compatible to eachother.

[NDR008]

Yeah, unfortunately the seller contacted me to recommend this one (as I bought the NodeMCU at the same time).

I agree with you on USB cables.

I had my raspberry Pi indicating power issues even though I tried 3 USB power sources including a 3A capable block.
Finally I found the cable was the limiting factor.

1st cable: always caused power problems.
2nd cable: caused occasional problems.
3rd cable: raspberry pi has not once throttled due to power shortage.

[karadn]

My sensor HC-SR04 still not working. I try with sepparate power the ultrasonic, but no luck.
Can you please check my connections and settings, now I power Wemos via USB adapter (5V).

20180116_163958.jpg (973.34 KiB) Viewed 27034 times

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[Shardan]

Hm.. looks good to me, as far as i can see.

That was my testing setup:
.

HC-SR04_on_Breadboard.jpg (460.82 KiB) Viewed 27027 times

.
It's same and worked, powered with a thick USB cable from my computer.
So what to do?
Check all cables first, a digital ohm meter helps a lot.
I've seen alot of these cheap DuPont cables having slack joints or no connection at all.
Breadboards are somewhat susceptible for bad contacts too.

Regards
Shardan

[Shardan]

Just for the record:

I've assembled my test setup again, uploaded the actual v2.0-20180116 for testing.
It worked out of the box.

[karadn]

So in settings must be:
- 1st GPIO set to GPIO-13, where Trig is connected.
- 2nd GPIO set to GPIO-12, where Echo is connected.

Is that ok?

[Shardan]

Yep..
Just it does not hurt if you swap accidentally, the device will just show 0.00.
If you doubt about that, swap the cables for a test.

[karadn]

The voltage that come from wemos 5v pin is 4.830V, it seams that is not enough for HC-SR04, because if I separate power 5V to ultrasonic it works now.
Is 4.8V realy too low for this sensor? So I must buy HC-SR04+ or P version?

[Shardan]

I didn't have a problem using the 5V from the WeMOS D1 or nodeMCU.

Anyways, the nodeMCU has a diode separating the 5V output from the 5V input from USB.
Diodes have a forward-loss so this might be a problem.

This is difficult to decide without hands-on on your device at a well equipped test site.

It might be a problem of the HC-SR04 itself also, tolerances of parts or something.
These boards are cheapest china made stuff so this might occur.
I'd get some HC-SR-04 from a cheap source like AliExpress and check them out.
5 pieces come around 3,50€ at AliExpress.

[TD-er]

The voltage that come from wemos 5v pin is 4.830V, it seams that is not enough for HC-SR04, because if I separate power 5V to ultrasonic it works now.
Is 4.8V realy too low for this sensor? So I must buy HC-SR04+ or P version?

Like Shardan already mentioned. If the wires powering the device are too thin, then the voltage may drop when trying to use more power.
It is then simply a resistor with a voltage drop over the wire which will increase when the current increases.

[karadn]

I have 3 sensors and with all is the same. I test sensor also with Wemos D1 pro and also not working.

[Shardan]

Then it gets difficult to check what's the reason without hand-on on a test site.

I suspice there is a problem with power supply, but honestly that's applied prophecy.
How do you supply power to the circuit? USB cable and power from PC?