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I have a TM1638 board with 8 seven-segment displays, 8 LEDS, and 8 buttons. Each time multiples leds are on, the board makes an annoying high pitch sound.

I'm controlling it with an Arduino Uno.

Should I worry about the sound and is it normal?

This is my board :

enter image description here

Glorfindel
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Dat Ha
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1 Answers1

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This thread is getting old but this LED&KEY device seems to still be fairly popular so this may still help someone else. I'm using one to control a radio receiver and the constant buzz can get pretty loud.

I found this article (A second look at the TM1638 LED & key controller) which mentions the same issue which was solved by inserting a 100Ω resistor between VCC and the VCC pin. I also added a 1000μF electrolytic capacitor across the VCC and GND pins (well, fairly close to them anyway). This quieted down the buzz a lot though it's still there. The resistor is key though the capacitor helps a bit.

I also tried moving the breadboard connections to a separate, smaller breadboard, away from the MCU and radio receiver chip and was able to use lower values (10Ω and 47μF). I was no longer able to hear the buzz at all.

techrah
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