Microsd Card; Analog Input; External I2C Connector; Table 10. Rs485 Related Solder Bridges - ST STM32G081B-EVAL User Manual

UM2403
JP8
Jumper
SB29,SB31
SB32
SB30
8.6.3
8.6.4
8.6.5
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Table 9. RS232 and RS485 related jumpers (continued)
PC5 is connected as RX signal without bootloader being supported when JP8 is set as shown
on the right (default setting):
PA10 is connected as RX signal with bootloader being supported when JP8 is set as shown on
the right (in this case, CN1 motor control connector must be open):
The RS485 communication is supported by RS485 transceiver ST3485EBDR which
connected to pin4 and pin9 of D-type 9-pins connector CN11 (share same connector with
USART1).

Table 10. RS485 related solder bridges

The external failsafe biasing are enabled when solder bridges SB29 and SB31 was closed
Default Setting: Not fitted
The bus termination is enabled when solder bridge SB32 is closed.
Default Setting: Not fitted
The AC termination is disabled when solder bridge SB30 is closed for high baud rate
communication.
Default Setting: Not fitted

microSD card

The 8-GB (or more) microSD card connected to SPI1 port (shared with color LCD) of
STM32G081RBT6 is available on the board. microSD card detection is managed by
standard IO port PC9 and it must be set with internal pull-up.

Analog Input

The two-pin header CN17 and 10K ohm potentiometer RV3 was connected to PB2 of
STM32G081RBT6 as analog input. A low pass filter can be implemented by replacing of
R111 and C90 with right value of resistor and capacitor as requested by end user's
application.

External I2C Connector

The I2C1 bus of the STM32G081RBT6 is connected to CN2 on the STM32G081B-EVAL.
The I2C functional daughterboard can be mounted on the CN2 connector and accessed by
the microcontroller through the I2C1 bus, it shares same I2C1 bus with Temperature sensor
U3 and DDC on HDMI_Source connector CN3 on legacy peripheral daughterboard.
The pull up voltage level of I2C1 bus is automatically decided by the daughterboard (the
legacy peripheral daughterboard or the UCPD daughterboard) on CN4 and CN5. If there is
Hardware layout and configuration
Description
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