UM1932 Rev 4
15/31
UM1932
Hardware layout and configuration
30
4.5 Audio
outputs
An audio DAC outputs the audio to a stereo headphone jack connector.
The digital audio interface SAI of STM32F469NIH6 is connected to the digital audio input
SDIN of the audio DAC. The STM32F469NIH6 controls the audio DAC via the I2C2 bus.
Note that the I
2
C speed of the audio DAC is 100 kHz max.
The PWM loudspeaker output SPKR_OUTA of the audio DAC is available at pins 15 and 16
of the extension connector CN12. Each of the two terminals of the external loudspeaker
must be connected to pins 15 and 16 of CN2 respectively. Ensure that the terminals of the
loudspeaker are not connected to the ground.
The port PE3 of STM32F469NIH6 enables the jack headphone output and/or the
loudspeaker SPKR_OUT. Providing the audio DAC registers are properly set, it allows the
power down of the loudspeaker and/or headphone outputs.
The I
2
C address of the audio DAC is 0x94.
4.6 Digital
microphones
Three STMicroelectronics MEMS digital microphones are available on the
32F469IDISCOVERY Discovery board. Two microphones can be used simultaneously in
stereo mode using the PDM mode. By default, microphones U2 and U6 are used and
connected to the DFSDM of the STM32F469NI microcontroller (solder bridges SB17
opened, and SB18 closed). The PDM clock is generated at port PD13 while PDM data are
received by the microcontroller at port PD6.
Instead of using the pair of microphones U2 and U6, it is possible to use the pair of
microphones U2 and U1. To enable this possibility the solder bridge SB17 must be closed
and SB18 opened.
Solder bridges locations are shown in
Figure 4: 32F469IDISCOVERY top side layout
4.7
USB OTG FS
An USB OTG full speed communication is available at connector CN13.
The 32F469IDISCOVERY Discovery board can be powered by the 5 V DC of this USB OTG
FS connection. When the 32F469IDISCOVERY is USB host, it supplies the USB peripheral.
In this case the board must be supplied by any of the following sources: ST-LINK/V2-1 USB
connector CN1 or pin VIN of ARDUINO
®
connector CN6. Refer to
for more details on each supply source.
The green LED LD8 lights up in one of these cases:
•
32F469IDISCOVERY works as a USB host and power switch U16 is switched ON.
•
V
BUS
is powered by another USB host when 32F469IDISCOVERY works as a USB
device.
Red LED LD9 lights up when over-current occurs.
