Humidity sensor with led alarm | Arduino project

This page contains Arduino Humidity sensor with led alarm source code. This project is good for someone who wants to make a humidity meter or hygrometer with led alarm if humidity and temperature over a threshold. It's easy to make and doesn't require an external power supply, just use power from an Arduino UNO R3 board (USB power compatible with this project).

Electronic components list:
1 x Arduino Uno R3
1x 20 x4 I2C LCD display
1 x AM 2320 humidity/temp sensor
1 x 5 mm led ( 2 x if you plan to use led for pin 13 instead built-in led)
1 x 1000 ohms resistor ( 2 x if you plan to use led for pin 13 instead built-in led)
Any USB power adapter, 500 mA current at least.

Here is the Arduino code:
AM 2320 library
LCD display i2c library

#include <Wire.h>
#include <AM2320.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3F, 20, 4);
AM2320 th;
int led2 = 12;

Modified lepy LP-A6fm amp

When I brought lepy LP-A6fm from my local store(Thailand) for under 10 $.  I though it's a good low-cost amp and I've found that this amp not bad at all. The bad thing I hate LP-A6fm is the amp have big pop noise when connecting to the power supply to the amplifier and the amplifier doesn't have any on/off switch. I thought the problem may come from JRC 4558 op-amp that doesn't have soft on/off function so I decided to change JRC 4558 to ne5532 op amp for low pop noise and change some capacitors for sound quality improvement.

Yeah! Let's start.

List of component:

1 x ne5532 opamp and 8 pins ic socket (for JRC 4558 op amp replacement, sound improve much).
3 x capacitor 100 uf muse FW(FG are better) for op amp power supply replacement and for main amp replacement
4 x 10 uf Elna Ccerafine or Silmic II electrolytic capacitors for the mellower sound.
1 mks 0.1 uf Wima capacitor(not see in the video because it attaches to preamp power supply under PCB board.
2 x 1000 uf/25 volts Elna(you can find better capacitor but for under 10$ amp you can think twice).

For the further upgrade, you can change power amp ic (TDA 7294 for 15 watts stereo power) too,but I'm okay with the amp now.

This video will show you lepy LP-A6fm modified for better sound and eliminated pop noise when power on/off

See non-modified lepy LP-A6fm for comparison


  1. This comment has been removed by a blog administrator.


Post a Comment