Arduino Controlled Bass Treble Volume and input Selector

Last time I have posted about how to control the LC75341 IC using arduino nano. And I also posted about how to modify the bass response of the LC75341 IC. This time I will be building a home amplifier for my TV, it will also feature a bluetooth reciever so that I can play via my phone.

All of the stuff I have put into this project is already posted on my site. Here are the links:

If you want to know more about this project, you may want to click on those links above. 🙂

Please Note that this is an on-going project. This project is not yet complete and is updated every now and then. If you don’t see this note anymore then it means the project is finally complete. 🙂


My goal was to have an amplifier for my TV with a 16×2 display for displaying the levels and also the spectrum analyzer. I also wanted to automatically lower the volume of the amplifier when a scene on the movie we are watching becomes too loud(i.e. fighting scenes with guns and bombs). This trick can be simple done with an arduino code.



The schematic below only shows the arduino and LC75341 part. The amplifier is in separate board. The control is very simple and used only 1 rotary encoder and one push button. The push button is used to select the parameter and the rotary encoder is used to adjust the level. The audio signal is sampled by arduino via pin A0 and A1. R10 – R13 is used to float the pin voltage to mid point(2.5V) to avoid negative voltage coming in to the arduino analog pins.


Build Report

This is a messy wiring at the moment because it is not yet finish. 🙂

It is working fine at the moment with some minor problems. The first problem is the hum noise but I managed to keep it at minimum, you won’t be able to notice it unless you put your ears on the speaker. I will post the informations on how to reduce hum noise on audio on the next few weeks maybe. The biggest problem I am encountering is the POP noise coming from the bluetooth module. Will update this blog once I found the culprit and solved it.

Arduino Code

Here’s what I was able to achieve for the moment:

  • Adjust Bass level
  • Adjust Treble level
  • Adjust Volume and gain
  • Select input
  • display output level(bar type)

The code can be downloaded on Download page here

Code improvements

There are lots of room for improvements here. I am not yet able to achieve what I want on this project as I have limited time and budget. Here are the list of improvements I am planning:

  • Display Spectrum Analyzer
  • Store and recall levels/settings – it should be able to recall previous levels and settings every power on
  • Automatic volume control – be able to reduce the volume when scene becomes load
  • Separate settings per input – recall settings per input.

There are many works to be done on this project. Hopefully I can finish this project within this month. You may want to like my facebook page for updates. 🙂

2 thoughts on “Arduino Controlled Bass Treble Volume and input Selector”

Comments are closed.