Week_9: Output Device

This week’s assignment was to add an output device to aboard; I chose a speaker to build my final project based on this weekly assignment.
An audio amplifier module was necessary to play the audio with quality sound. My understanding of an audio amplifier will reduce noises and amplify the overall volume based on gains.




The lab had an LM386 audio amplifier chip but not the complete board.
So I followed the tutorial to build my audio amplifier board. Firstly, I used a breadboard to test the function, then moved on to designing a board, milling aboard, and soldering components.




This board uses a 1000uf capacitor, which is more than enough to kill an adult.
Quickly, I got scared and chose not to use this board. Instead, I bought MAX98306(Adafruit Stereo 3.7W Class D Audio Amplifier), and it gave me a small peace of mind.




On the hackster.io site, there was a good tutorial for esp32 and speaker.
I put them together on the breadboard following the tutorial then uploaded a looping audio code through Arduino.
No sounds came out at first, so Rob helped me check the circuit using an oscilloscope. The problem was that I missed putting all the components that followed with
MAS98306, and some were not connected because it was simply on the breadboard. After soldering all connecting circuits, it started to play looped audio.





Building own audio amplifier

ESP32 + speaker tutorial


Audio amplifier trace png
Audio amplifier exterior png
speaker(receiver)_arduino code