Leds; Pushbuttons; High-Brightness Led Dimming With A Buck Converter - ST STM32F334C8 User Manual

Hardware layout
5.3

LEDs

• LD1 PWR:
The red LED indicates that the board is powered.
•
LD2 COM:
The LD2 default status is red. LD2 turns to green to indicate that the communications
are in progress between the PC and ST-LINK/V2-1.
•
User LD3:
The red LED is a user LED connected to the I/O PB6 of the STM32F334C8T6.
•
User LD4:
The orange LED is a user LED connected to the I/O PB8 of the STM32F334C8T6.
•
User LD5:
The green LED is a user LED connected to the I/O PB9 of the STM32F334C8T6.
•
User LD6:
The blue LED is a user LED connected to the I/O PB7 of the STM32F334C8T6.
5.4

Pushbuttons

•
B1 USER:
User/wake-up button connected to the I/O PA0 of the STM32F334C8T6.
•
B2 RESET:
The push-button connected to NRST is used to RESET the STM32F334C8T6.
5.5

High-brightness LED dimming with a buck converter

The STM32F334 Discovery integrates a high-brightness LED dimming feature. This function
is designed with on-chip peripherals MCU to reduce the number of external components
generally included in analog component-based solutions for LED dimming.
The default LED voltage supply is the 5 V from the 5V_OUT signal or can be provided by an
external voltage through CN4 (Vext signal) and by removing the solder of SB18. This
external voltage must be between 5 and 15 V.
LED information:
•
Reference LE-CWC12100-D, 1 W, Everluck
•
VF = 2.8 V typical
•
IF = 350 mA maximum
To design a high-brightness LED dimming application, refer to the following documentation
and firmware:
•
For details concerning I/O ports, refer to the STM32F334C8T6 datasheet.
• For information on software development, refer to the DISCOVER application software
on www.st.com/en/product/32f3348discovery.
•
For more detail concerning high-brightness LED dimming, refer to the application note
High brightness LED dimming using the STM32F334 Discovery kit (AN4885).
•
The STM32Cube library is available from www.st.com/en/product/32f3348discovery.
Warning: The high brightness of this LED can be very dangerous for your eyes.
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