• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 79 subscribers
  • Views 706 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Using the MSP430 to control the LED Driver TLC5940

Daniel Gore
Prodigy 90 points

Other Parts Discussed in Thread: TLC5940

The TLC5940 requires a greyscale clock of unspecified frequency to properly drive the PWM. The frame rate is 4096 clocks, thus the GSCLK source must also count the ticks and generate a ISR. I am interested in using the MSP430 series of controllers for the job, as the application is a battery powered device and must have a low-power mode, as the MSP430 offers. The challenge is sourcing the 16Mhz clock (tied to Timer_A) to the GSCLK in the TLC5940.

Is there any expertise in the community with this combination?

-DeveloperDan

  • 0
    Guru 227245 points

    Daniel Gore said:
    The challenge is sourcing the 16Mhz clock (tied to Timer_A) to the GSCLK in the TLC5940.

    It's no challenge at all. Almso tall MSPs support outputting the current SMCLK or ACLK to a dedicated port pin.
    You can then directly connect it to the TLC.

    The pins on which the clock signals are available (sometimes more than one) differ. See your specific MSPs datahseet for details. Look for SMCLK or ACLK (along with e.g. Px.y) in the pin signal list.

    However, 16MHz is quite fast. it results in ~4kHz 'display' frequency, which causes a lot of on/of transitions per second and therefore much wasted energy. You could go by a factor of 8 lower (=500Hz)  and still be way above the human recognition threshold (which is actually around 25Hz, so even 50Hz would be enough)

**Attention** This is a public forum