Hardware layout and configuration
UM1065
Doc ID 018640 Rev 4
2.12 MEMS
A ST MEMS device LIS302DL is connected to I2C1 bus of STM32F217IGH6 on the board.
2.13 Potentiometer
There is one 10 Kohm potentiometer RV1 connected to PF9 of STM32F217IGH6 on the
board.
2.14 ADC
Two test points (TP3 AIN-) and (TP4 AIN+) are placed close to port PC1 of the MCU
allowing precise measurements on ADC1, ADC2 or ADC3 channel 11. As PC1 is also used
as current A input on the motor control connector it is recommended to remove R219 to
optimize noise immunity on this input.
A potentiometer RV1 is connected to PF9 of STM32F217IGH6. If needed, a low pass filter
(R74 and C59) can be placed on this input to reduce the bandwidth of the analog input PF9.
It is also possible to place the Ethernet PHY (U5) in low power mode in order to reduce the
noise induced by this high frequency peripheral. Power down pin (MII_INT in the schematic)
is connected to PB14 of the MCU, so this I/O can be to be configured as output low during
analog precision measurement.
2.15
USB OTG FS
The STM3221G-EVAL evaluation board enables USB OTG full speed communication via a
USB micro-AB connector (CN8) and USB power switch (U1) connected to VBUS. The
evaluation board can be powered by this USB connection at 5 V DC with a 500 mA current
limitation.
LED LD6 indicates that either:
●
Power switch (U1) is ON and the STM3221G-EVAL functions as a USB host or
●
VBUS is powered by another USB host while the STM3221G-EVAL functions as a USB
device.
LED LD5 indicates an over-current.