12 LED Charlieplexing Knight Rider w/ 8bit PWM

12LED Charlieplexed Knight Rider w/ 8bit PWM

Category:

Science & Technology

Tags:

• charlieplexing
• freescale
• RS08

[tonysofla]

Below I will show the Anim data for the knight rider effect

I repeat 2048 and 1 a few times to get the pause effect at each end.

Two Bytes (a 16bit Word) uses the lower 12bits to light up any LED.

The first 3 words have the upper unused 4 bits (0-15) representing:

Anim lenght, Anim Speed and last the Anim Fade Speed.

[tonysofla]

ORG ROMStart

dc.w 1 +(15<<12),2 +(3<<12),4 +(7<<12)

dc.w 8,16,32,64,128,256,512,1024

dc.w 2048,2048,2048,2048,2048,2048

dc.w 1024,512,256,128,64,32,16,8,4,­2,1,1,1,1,1

[tonysofla]

Using only for 4pins on a freescale RS08 low-end MCU to control 12 LED.

Only 1 LED is on at anytime resulting in a 8% duty mode.

This duty mode is further divided in to 256 steps for a dimming effect.

No need to use resistors in this case.

The animation:

12bit animation control,

so any number of LEDs can turn on at the same.

each animation have its on speed control.

Global fade, all LED are faded down to 0.

each animation have it's fade speed control.