UM2403 Rev 1
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UM2403
Hardware layout and configuration
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8.7
Peripherals on legacy peripheral daughterboard
8.7.1
LDR (Light dependent resistor)
The VDD is divided by resistor bridge of LDR VT9ON1 and 8.2 K resistor and connected to
PA1 (/ADC IN1) as shown
on STM32G081B-EVAL Evaluation board.
Figure 9. GP comparator 1
It's possible to compare LDR output with ¼ band gap, 1/2 band gap, 3/4 band gap, band
gap and DAC1 OUT and to connect LDR output to ADC IN1 for AD conversion.
8.7.2 Temperature
sensor
A temperature sensor STLM75M2F is connected to the I2C1 bus of the STM32G081RBT6,
and shares same I2C1 bus with EXT I2C connector (on mother board) and DDC on
HDMI_Source connector CN3 (on legacy board).
I2C address of temperature sensor is 0b100100(A0), A0 can be 0 or 1 depends on the
setting of SB7.
Note:
The temperature result measured from STLM75M2F would be a little higher than the
ambient temperature due to the power dissipation of components on the board.
Table 12. Temperature sensor related solder bridge
Solder Bridge
Description
SB7
I2C address A0 is 0 when SB7 is open.
(Default setting)
I2C address A0 is 1 when SB7 is closed.
