70 leds one at a time


I need to control 70 leds. One at a time. Can you help me? what materials do I need for this? thank you very much.

5 x "4 TO 16 LINE DECODER/DEMULTIPLEXERr" like the 74154 (80 pins) 1 x "3 TO 8 LINE DECODER" like the 74138 (to enable one of the 5 16-bit decoders)

7 data pins to address the two levels of selector.

If you hook a PWM line to one of the gate inputs on the 74154's you can fade each LED in and out.

Or an 8x8 matrix driver chip and an 8-bit shift register for the last few LEDs. Or a 5x7 matrix driver chip like the MAX6953, can do 4 x 35 LEDs.

Thank you very much.

Have you or know any good tutorial to do this?.

or 2x M5451 chips - can drive 35 LEDs each.

The CC-Shield uses two of them so you could use the code from that as a starting point: http://effluviaofascatteredmind.blogspot.com/2009/02/my-first-arduino-shield-arrived.html

If you go to www.arduino.cc, select Learning, search for 8x8 matrix, you will find some links.

This is one of them
To me there should be current limiting resistors in there somewhere.
Instead of arduino pins, you could drive with shift registers, etc. as discussed above.