Wiring

You can perform a couple tests on the amplifier without hooking up the i2c pins - it'll be fixed at 6dB and the default AGC is on but you should be able to hear audio through speakers

Power


You can power the amplifier from 3-5V DC. If you want to use a wall adapter, a 2.1mm terminal block is handy
or you can use a 3xAA battery holder as we do in the photos below

Connecting Audio

Testing the amplifier is really easy - no firmware or special configuration required to get a little audio out. In these images we'll assume you're using a breadboard but the wiring is the same if you soldered connections directly.

The easiest way to test your amplifier is to connect a 3.5mm audio pigtail cable to the audio inputs. Connect Right to R+ and Left to L+ then since a 3.5mm audio cable is single-ended, connect the ground wire to both R- and L-

You can connect the power to the board via either a breadboard rail with 3-5VDC on it (say from an Arduino power supply or battery pack)
If you want to plug in a 3.5mm jack into the breadboard instead of having the cable pigtail, you can wire up a stereo jack as shown below. Tie ground to R- and L- and left and right to L+ and R+
With just an audio source you can sort of see how the AGC system works - the amp will try to 'normalize' the volume to be constant
This guide was first published on Feb 07, 2014. It was last updated on Feb 07, 2014. This page (Wiring) was last updated on Apr 20, 2019.