Controlling 12 - 24 LEDs: TLC5940, TLC5947, ...

Using Arduino LEDs and Multiplexing
1

I'm just starting with LEDs. First I thought I use a SN74HC595N shift register, but then I found the TLC5940 (16-Channel LED Driver w/EEprom DOT Correction & Grayscale PWM Control)

What I want to achieve: Control 12 (maybe later 24) LEDs, (turn on/off and dim them).

TLC5947 (has 24 channels) would be perfect imho. But there is no DIP package - and the only breakout board I found is from Adafruit - and pretty expensive.

Are there alternatives?

2

and the only breakout board I found is from Adafruit - and pretty expensive.

Well if $15 is considered expensive what budget are you on?

The alternative is to buy an undedicated breakout PCB from eBay and solder it on yourself, it is not hard.

3

Grumpy_Mike:
Well if $15 is considered expensive what budget are you on?

The alternative is to buy an undedicated breakout PCB from eBay and solder it on yourself, it is not hard.

Compared to the 5$ of the chip $15 is quite a lot. And the Adafruit breakout board has stuff that I don't need (e.g. the voltage regulator).

4

If you can't solder a surface mount chip then the $10 is for some on to do it for you.

An other alternitave is to use the 5mm neopixels.

5

In my project, I first used the TLC5940, but then I found the PCA9685 which I think is much easier to use, since it communicates via I2C and adafruits library works great.

I bought some PCA9685 in TSSOP28 package from ebay (Link), adapters (Link) and soldered the chips as shown in this video: Drag soldering SMD parts with a flux pen.

For my project, this is the best solution.

6

vile:
In my project, I first used the TLC5940, but then I found the PCA9685 which I think is much easier to use, since it communicates via I2C and adafruits library works great.

I bought some PCA9685 in TSSOP28 package from ebay (Link), adapters (Link) and soldered the chips as shown in this video: Drag soldering SMD parts with a flux pen.

For my project, this is the best solution.

Thanks a lot for your post! The PCA9685 indeed seems to be a very good choice:

  • 2.3 V to 5.5 V
  • inexpensive (under 2$ from Farnell)
  • TSSOP28 (TLC5947 has TSSOP32 and the adapters are way more expensive than TSSOP28 ones)
  • I2C

It's just: I've never hand soldered SMD before. Dave Jones has a very nice video covering different techniques: EEVblog #186 - Soldering Tutorial Part 3 - Surface Mount - YouTube. So I might just give it a go.

7