Hardware layout and configuration
UM2271
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DocID030906 Rev 2
10.13.2 32L4R9IDISCOVERY as USB host
When the board works as a USB host, it supplies the 5 V to the USB peripheral using one of
the following sources:
•
ST-LINK/V2-1 USB Micro-B connector CN13 (jumper put in STLK location of JP4)
•
an external 5 V source connected to pin 5 of the Arduino connector CN16 (jumper put
in ARD location of JP4)
•
an external source between 7 V and 11 V, connected to VIN pin of Arduino connector
CN16 (jumper put in E5V location of JP4)
The green LED LD8 is lit on to confirm the presence of the 5 V source.
The power switch STMPS2141STR is controlled by the port MFX_GPIO13 to deliver the 5 V
power to the USB device connected to the USB connector CN9. When MFX_GPIO13 is
pulled down to ground, the power switch is closed, and the green LED LD6 confirms the 5 V
presence for the USB device. The red LED LD7 FAULT is lit when an over-current occurs.
For more details please refer to
10.14
Octo-SPI Flash memory
A 512-Mbit Octo-SPI user Flash memory (MX25LM51245GXDI00 from MACRONIX) is
connected to OCTOSPIM_P2 interface of STM32L4R9AI. By default, OCTOSPI_RESET of
Flash memory has been connected to the general reset of 32L4R9IDISCOVERY.
See
for possible Octo-SPI Flash configuration change.
Note:
Limitation: the Octo-SPI Flash memory is not compatible with JP7 setting at +1V8.
10.15
Virtual COM port
The serial interface USART2 is directly available as a virtual COM port of the PC, connected
to the ST-LINK/V2-1 USB connector CN13. The virtual COM port settings are configured as
follow: 115200 bps, 8-bit data, no parity, one stop bit, no flow control.
10.16 Buttons
and
LEDs
The blue button B2 is a four-directions joystick with a selection mode when pressed in the
center. The logic state is high when one of the five-position switch (left, right, up, down,
selection) is pressed. The center position (Select function) is connected to a wake-up pin of
the microcontroller PC13. The other four directions are mapped on MFX GPIOs.
The black button B1 near the display is the Reset button. It is used to reset the board and
can wake-up MCU from standby and shutdown IDD measurement modes.
Two user LEDs located near the camera connector CN2 are available for the user (see
): LD1, LD2, from left to right, with orange and green color respectively. To light on a
LED, a low logic state 0 must be written in the corresponding GPIO.
•
LD1 (orange) is managed by MFX function
•
LD2 (green) is managed by STM32L4R9AI main MCU
