7.12
Buttons and LEDs
The B1 black button located on the top left side is the reset of the STM32L462REY6TR microcontroller. Refer to
.
The B2 blue button located on the top left side is used as a digital input or as an alternate wake-up function.
When the button is depressed the logic state is LOW, otherwise, the logic state is HIGH.
Three LEDs (LD1, LD2, and LD3), located on the top left side are available for the user. To light a LED a logic
state HIGH must be written in the corresponding GPIO. As the GPIOs can be connected to timers in the chip, the
user may use the PWM function to control the brightness of LEDs.
Table 4.
Button and LED control port
Reference
Color
Name
Comment
B1
Black
Reset
-
B2
Blue
Wake-up
Alternate function Wake-up
LD1
Green
User LED1
PC6
LD2
Red
User LED2
PB15
LD3
Blue
User LED3
PB14
LD4
Green
LED4
PSM_IND, controlled by the modem, lights
ON when the modem is not in low
‑
power
mode, and OFF when the modem is in
low
‑
power mode.
LD5
Green
LED5
TX_IND, controlled by the modem
reference
Bicolor (red and green)
ST-LINK COM
Green during communication
LD7
Red
Fault Power
Current upper than 750 mA
7.13
I
2
C addresses of modules used on MB1508
displays the I
2
C read and write addresses for the modules that are connected to the I2C1 bus.
Table 5.
I
2
C addresses for each module
Modules
Description
SAD[6:0] + R/W
I2C write address
I2C read address
HTS221
Capacitive digital sensor for relative
humidity and temperature
1011111X
0xBE
0xBF
LPS22HH
MEMS nano pressure sensor
1011101x
(SDA[0]=1])
0xBA
0xBB
LSM303AGR
3D accelerometer and 3D
magnetometer
0011001x
(Linear
acceleration)
0x32
(Linear
acceleration)
0x33
(Linear
acceleration)
0011110x
(Magnetic field)
0x3C
(Magnetic field)
0x3D
(Magnetic field)
M24128-
DFMN6TP
128-Kbit serial I
2
C bus EEPROM
1010000x
(Memory array)
0xA0
(Memory array)
0xA1
(Memory array)
1011000x
(Identification
page)
0xB0
(Identification
page)
0xB1
(Identification
page)
UM2743
Buttons and LEDs
UM2743
-
Rev 1
page 20/58