UM10317_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 15 December 2008 8 of 11
NXP Semiconductors UM10317
PCA9633 demonstration board OM6282
8.2 Color mixing and blinking LEDS
To set-up a blinking demo, repeat step1 through step 7 as in Section 8.1, then do the
following:
1. In the Mode 2 selection window, check the ‘Group Control’ box to change the mode to
blinking.
2. Select a color using the PWM cursors.
3. To set a blink cycle, use the GRPPWM cursor to select the duty cycle and use the
GRPFREQ to select the blink frequency.
4. For example, set the GRPPWM to 0x05 (1.95 % duty cycle) and the GRPFREQ to
0x17 (1 second) for a short blink every second (see Figure 6).
5. Change the GRPPWM to 0x80 (50 % duty cycle) and the LED will be on for
0.5 seconds, repeating every second.
6. Change the color of the LEDs by selecting a different PWM value for each LED.
7. Set the GRPPWM to 0x52 (32 % duty cycle) and the GRPFREQ to 0x01
(0.08 second) and observe the pattern.
8. Change the PWMn values, GRPPWM and GRPFREQ values to create different blink
patterns.
9. Change the LEDOUT register on one LED output to be controlled only by its PWM, for
example, ‘LED1 controlled by PWM1’.
10. Change the blink rate and observe the results.
For support, please send an E-mail to: i2c.support@nxp.com
Fig 6. Example of short blink every second