B4R Question Clicking sounds in buzzer

[hatzisn]

Good morning,

I have two questions:

1) I have connected a buzzer to a WeMos D1 mini in pin D8 (pull down) but it does some clicking sounds (like click click) when it doesn't play any sound. Anyone know how can I address that? I though by connecting it to a pull down pin would solve the problem but it still appears.
2) I have bought some buck converters that take in 220V ac and provide 5V 2A. I intend to power a wemos d1 mini and a double relay. Is there any possibility that by providing these values to the five volts pin of the wemos I will burn it? I mean with the 2A. Is there also any health hazard utilizing this kind of amperage with 5 volts? (I suppose not since it is DC but someone more experienced would be very welcomed if he answered this)

 

[rbghongade]

Dear friend,
This may help you:
1) Try using negative logic while driving the buzzer by connecting the positive terminal of the buzzer to +3.3V and negative terminal to the GPIO of the Wemos board. You will have to output a "low" to activate the buzzer .
2) There won't be any problem with using the buck converter, but make sure that the converter is a good quality one with isolation. This will ensure that high voltage side and low voltage side are properly isolated. No issues with the current rating as higher the current rating , better is your power supply.
( I assume you are using an active buzzer)

 

[hatzisn]

Hello @rbghongade and thank you very much for answering. I will try your solution within the day but for now I must tell you that I use the library rESP8266Tone as seen in the next link which by itself uses the tone command of Arduino.

Play tone in ESP8266.

Yesterday I tried to play a tone to a passive buzzer using the rTone library in a WeMos D1 Mini v3.0.0 module.. It was a complete fail because there is an inconsistency between Esp8266 boards and rTone library and B4R/Arduino reports that interrupt.h file is missing. So I figured a way around...

www.b4x.com

tone() - Arduino Reference

The Arduino programming language Reference, organized into Functions, Variable and Constant, and Structure keywords.

www.arduino.cc

I suppose (according to the previous link - tone() ) that that your solution will work as the signal of this library will be shifted by half a cycle and this won't have any unwanted consequences to the buzzer... Right?

I use a passive buzzer in my project. As far as it has to do with the buck converter this is the product. Do you think that the isolation is good enough from the pictures?

1.34US $ 5% OFF|AC DC Converter 110V 220V to 5V 2A Buck Voltage Regulator Low Ripple Switching Power Supply Module|Switching Power Supply| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[rbghongade]

Hi,
Cant open the page as AliExpress is blocked in my country. But I think the buck converter is non-isolated given the price!

 

[agraham]

In my experience anything Chinese, cheap and mains powered is to be handled at arms length. They will cheerfully forge CE and other markings and I have seen examples where the isolation distances are definitely too small to conform to European safety specs. The quality of the isolation transformer too can't easily be established but that one looks double wound rather being double bobbin which makes me nervous.

 

[hatzisn]

Thank you both for answering.

@rbghongade I have tried your solution with the 3V3 to plus of the passive buzzer and minus to D8. I have set the logic level of D8 to high and I was expecting that since it drives the pin with tone() command the lows would create the sound but it didn't work. I found though what is causing the clicking sounds and this is the following. My project utilizes also a LCD1602 and I power both the LCD and the WeMos from an outside source which provides 700mA and 5V. Obviously it is power related because if I remove WeMos from the power and power it with an external USB the clicking sound disappears.

@agraham I am not familiar with the terms in English as I have learned them in Greek. Double wound means the first bobbin in the other and double bobbin means separate bobbins wrapped around the copper that's placed inside them?

 

[agraham]

They may not be the strictly accurate words but double wound to me means that the secondary is wound on top of the primary and the the two are usually isolated only by a thin flexible separator and the insulation of the wire. Double or split bobbin is where the windings are physically separated by being wound on separate bobbins which gives much higher isolation between primary and secondary. Like these high isolation examples.