MEMS Microphones (PDM)#
The I/O Port and Control Port support the connection of MEMS microphones via PDM encoding. While it is possible to connect up to six microphones, the operating system is already prepared for two microphones starting from Software Release 1.0.2. To enable them, the device tree overlay dp-dpp-lxx-8p-micfil-overlay.dtbo must be loaded as described in Applying Device Tree Overlays. One data signal can receive up to two microphones differentiated by signals on the rising and falling edge of the clock signal. Please refer to the datasheet of your desired microphone for details. The following table describes the available pins.
Pinout and Signal Table#
Connector |
Pin # |
Signal |
Microphones |
|---|---|---|---|
I/O Port |
18 |
PDM_CLK |
|
I/O Port |
9 |
PDM_DATA0 |
1+2 |
I/O Port |
23 |
VDD 3V3 |
|
I/O Port |
24 |
GND |
|
I/O Port |
1 or 2 |
PDM_DATA1 |
3+4 1) |
Control Port |
7 |
PDM_DATA2 |
5+6 1) |
1) If more than 2 microphones are required, please contact the Support for the required operating system adaptions.