NXP Semiconductors PCA9685, Руководство пользователя, Страница: 9 / 15

UM10574 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
User manual Rev. 1 — 1 April 2014 9 of 14
NXP Semiconductors
UM10574
PCA9685 demonstration board OM13332
3. For LED output that directly connects to LED as the demo board design, the INVRT
bit in MODE2 register must be set to 1 by checking the ‘Output not inverted’ to ‘Output
inverted’ and the OUTDRV bit in MODE2 register must be set to 0 by checking the
‘Totem pole outputs’ to ‘Open-drain outputs’ to make sure all LEDs are completed
OFF state as shown in
Figure 6 .
4. The device configuration screen is displayed by clicking the following options:
– ‘PWM 0 to 3’ individual brightness control for LED0 to LED3
– ‘PWM 4 to 7’ individual brightness control for LED4 to LED7
– ‘PWM 8 to 11’ individual brightness control for LED8 to LED11
– ‘PWM 12 to 15’ individual brightness control for LED12 to LED15
– ‘Control Registers’ all LED[0:15] brightness control and Prescale for all LEDs
output frequency as shown in
Figure 7
5. In Figure 6 , uncheck the ‘LEDn Full Off’ box (lower bottom), adjust both ‘LEDn ON’
and ‘LEDn OFF’ bar for dimming/brightness effect, also move LED1 ON/OFF to
control red, LED2 ON/OFF to control green, LED3 ON/OFF to control blue for color
mixing.
Remark: The LED ON time, which is programmable, is the time to assert the LED output
and the LED OFF time, which is also programmable, is the time to negate the LED output.
Fig 5. Drop-down menu selections