Data Sheet

4-pin stereo terminal

We recommend using a 4 ohm, 3 watt speaker. A higher ohmage results in a much quieter output.

The stereo terminal is a 4-pin 2.54mm-pitch terminal connector for stereo speakers. Wire functions are as follows

(from left to right, as shown in figure 5):

1: Speaker left positive

2: Speaker left negative

3: Speaker right positive

4: Speaker right negative

Figure 5. Stereo speaker terminals

MicroSD slot

The MicroSD card meets the SD/SDIO standard, up to version 3.0. It can be used as expanded memory for the system

or as the disk for the system image. If the entire system fails, you can use the SD card to reflash U-Boot onto the board

(see the flashing instructions).

Version 1.6 (July 2020)