LP5860: Some LEDs doesn't light up

Danilo A.

Part Number: LP5860
Other Parts Discussed in Thread: USB2ANY,

Hi Team,

Our customer built an LP5860 prototype board using the SPI Interface. He wants to test the prototype board so I told him to connect the SPI port of USB2ANY development tool to the corresponding SPI port of LP5860. I also told him to connect the IFS pin of the LP5860 to VCC. When he ran the LP586x GUI only 66 of the 198 LEDs lit up as shown in the picture below. Please see attached matrix and schematic diagram.

1500-AMZ-0001-00_REV-01_LED.pdf

Is the GUI capable of lighting up all LED in this setup? What could be the cause of the other LEDs not lighting up?

Regards,

Danilo

over 2 years ago

0 Aaron Bing over 2 years ago

TI__Expert 4120 points

Hi Danilo,

The GUI is capable of lighting up all 157 LEDs. Could you help our customer check if the Dot_grp_sel registers are used and pwm_bri registers are correctly configurated?

Best Regards,

Aaron Bing

0 Reddy over 2 years ago

Prodigy 110 points

No, I haven't configured mentioned registers. Could you please help with instructions To test all the LEDs with the evaluation software? Thank you.

0 Aaron Bing over 2 years ago in reply to Reddy

TI__Expert 4120 points

Hi Reddy,

The SPI communication looks fine to me. Kindly set all pwm_bri registers to 0xFF and see if all LEDs are turned ON. In addition, please take Section #3.3 LED Control Page in the LP5860EVM User Guide as an alternative way to configurate those registers.

Best Regards,

Aaron Bing

0 Reddy over 2 years ago

Prodigy 110 points

HI Configured the registers as you mentioned in the previous reply. All the LEDs are turning ON. Thank for your support.

0 Aaron Bing over 2 years ago in reply to Reddy

TI__Expert 4120 points

Hi Reddy,

No prob :)

Best Regards,

Aaron Bing

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LP5860: Some LEDs doesn't light up