Multiple single colour 5v leds; most effective solution?

[Pensive]

Hi guys

I'm going to have about 34 leds to illuminate, most of which will be 5v LEDs. They are not colour LEDs at present.

Dimming would be useful for most of them.

I looked at this library:https://www.pjrc.com/teensy/td_libs_OctoWS2811.html

The addon device seems to solve my 5v stage issue but it would waste ram on colour leds i dont really need. Ram is going to be in short supply on my project (i'll be posting my plans soon, you'll see what i mean).

I already have my buttons sorted on a ps2 arcade interface, but i will also have the audio addon card w/sd and a small 3 digit 7 segment display. So i'll be running short on pins fairly soon.

Is there a cheap i2c chip with 32 5v output pins i could use? And does it do native pwm? Or can i program it to do pwm manually?

I appreciate i am getting to the point where your advice might change given full visibility of the project so i'm going to do a photoshop mockup tonight and post a project plan but its always good to hear the options.

Hint: i am more interested in plug and play solutions if possible, hence why i went for a mini-pac with wiring kit to get my 32. Cost is less of an issue; wondering if another Teensy is in order as a slave.....

Rgds

Jon

 

[MichaelMeissner]

Adafruit sells an i2c board that can control 16 individual LEDs or servos with PWM. Note, the board off-loads PWM from the microprocessor. There are 6 address select bits, so you could put a total of 62 boards on an i2c bus (992 leds): https://www.adafruit.com/product/815.

If you would prefer SPI over i2c, they make a 24 led board that is tuned towards leds ony and not servos: https://www.adafruit.com/products/1429

 

[Pensive]

Thanks Michael

2 of those would be grand

I think i'll need to ask the SPI /i2c question in context of the whole project another time. Plus i like to do a thorough google before i bother you kind and knowledgable folks. thanks