Audio; Can Bus - Cherry Theobroma Systems PUMA SOM-RK3399-Q7 User Manual

echo out > /sys/class/gpio/gpio156/direction
echo 1 > /sys/class/gpio/gpio156/value
The GPIO will be set to a value of 1 (high at 3.3V).

3.15 Audio

The board provides two audio connectors for input and output. Line-in is on top and Headphones is on bottom of the audio
connector.
Additionally, an expansion connector for I2S audio is available on the bottom row of the board:

3.16 CAN Bus

The board provides a CAN connector on the bottom row.
v1.7
Page 16
Fig. 3.16: Audio input/output port
3V3
GND
I2S_CLK
I2S_SDO
I2S_DAT
Fig. 3.17: Connecting to the audio expansion connector
3V3 LDO
I2S_RST#
I2S_WS
I2S_SDI
I2C_CLK