ST 32F412GDISCOVERY, User Manual

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UM2032 Rev 3 23/40
UM2032 Hardware layout and configuration
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5.10.1 32F412GDISCOVERY is USB device
When the 32F412GDISCOVERY is USB device, the Discovery kit is powered by the 5 V of
the CN3 USB OTG FS Micro-AB connector. In this case a jumper must be put in USB
location of jumper JP3 and the green LEDs LD7 V
BUS
and LD6 PWR light on to confirm the
5 V presence.
5.10.2 32F412GDISCOVERY is USB host
When the 32F412GDISCOVERY is USB host it supplies the 5 V for the USB peripheral
using one of the following sources:
•
ST-LINK/V2-1 USB Micro-B connector CN6, putting a jumper in STLK location of JP3
•
An ex5 V source connected to pins 3 or 4 of the extension connector P2, with
no jumper in JP3.
•
An ex5 V source connected to 5 V pin of ARDUINO
®
Uno V3 connector CN2,
with no jumper in JP3.
•
An external source b7 to +11 V connected to VIN pin of ARDUINO
®
Uno V3
connector CN2, putting a jumper in E5V location of JP3.
The green LED LD6 is lighted to confirm the presence of the +5 V source.
The power switch is controlled by the port PG8 of STM32 to deliver the 5 V power to the
USB device connected to the USB connector CN3. It is recommended to use PG8 in open-
drain mode. When PG8 is closed to ground, the power switch is closed, and the green LED
LD7 confirms the 5 V to the USB Device.
The red LED LD8 FAULT is lit when an overcurrent occurs.
For more details refer to Section 5.3: Power supply .
5.11 microSD™ card
microSD™ cards with a capacity of 4 Gbytes or more can be inserted in the receptacle
CN13. The four bits of the SDIO interface including CLK and CMD signals of the
STM32F412ZGT6 are used to communicate with the microSD™ card. The card detection is
read by the GPIO PD3: when a microSD™ card is inserted, the logic level is 0, otherwise it
is 1.
Note that port PC9 used as uSD_D1 can be routed also to the pin 46 of the extension
connector P2, by closing the solder bridge SB43 for other usage like the alternate function
MCO2. Therefore the use of the microSD™ card is exclusive with MCO2 output.
Limitations: The microSD™ card is not working when the STM32 is supplied with 2 V.
5.12 I
2
C extension connector
The I2C2 bus is available on the I
2
C extension connector CN10. I2C2-SDA (port PB9) is
available on pin 1 and I2C2-SCL is available on pin 3. Pins 5 and 7 of CN10 are the VDD
and GND supplying the microcontroller. I2C2 voltage levels follows also VDD.