Power Pins

These pins are available both through the STEMMA connector, and as through-hole pads.

• VIN - This is the power pin. To power the board, provide 3V-5VDC.
  
• GND - This is common ground for power.
  

Audio Input

This pin is available both through the STEMMA connector, and as a through-hole pad.

• SIGNAL - This is the audio input pin. Connect to a line level (~ 1Vpp) voltage audio signal to send audio to the amp. There is capacitive AC coupling so you can have a DC offset.

Audio Output

• VO+ - Connect the power wire on a compatible 4-8Ω speaker to this pin. 
• VO- - Connect the ground wire on a compatible 4-8Ω speaker to this pin.

Bridge-Tied Load outputs mean you cannot connect these to another amplifier - they must connect to a speaker directly!

STEMMA Connector

The STEMMA connector is located on the left side of the front of the board, below the PAM8302 on the board silk. You can use a STEMMA JST PH 2mm 3-pin cable to connect the amp to your microcontroller board, for example this cable to connect using a breadboard.

The STEMMA connector has the following pins:

• SIGNAL (white wire) - Audio input pin - line level AC or DC coupled input
• VIN (red wire) - Power pin, 3-5VDC
• GND (black wire) - Ground pin.

Terminal Block

The terminal block is located on the right side of the front of the board, between the + and - on the board silk. Your terminal block may be blue or black.

The block has the following terminals:

• -  - This terminal is towards the top of the board, and is located next to the - symbol on the board silk. It is the same as the VO- pin. Connect the ground wire on your speaker to this terminal.
• + - This terminal is towards the bottom of the board and is located next to the + symbol on the board silk. It is the same as the VO+ pin. Connect the power wire on your speaker to this terminal.

Volume

The silver trimpot sitting top-center on the front of the board, labeled Volume, allows you to adjust the volume on the board down from the default 24dB gain.

Power LED and Jumper

• Power LED - On the front of the board, below the STEMMA connector on the left, is the power LED, labeled ON. It is a green LED.
• LED jumper - In the lower right corner on the back of the board is a jumper for the power LED. If you wish to disable the power LED, simply cut the trace on this jumper. To enable it again, solder the pads back together.