Matrix user forums

I am looking at controlling a number of leds and the only way I can see to do this is by using a second microcontroller. I'm looking at about 40 leds which will light in various combinations.

The combination will depend on a keypad selection. This keypad selection will send serial code from the 1st ucontroller to a Vmusic2 module as well as illuminating one of 3 leds to indicate a status.

The other 40 x LEDs are to hightlight the button/keypad key pushed. In reality the keypad will ber a larger matrix of switches wired to simulate the keypad.

Any thoughts/hints on what i can explore

Cheers and Regards

Ian b

Hello Ian

Ok you can do something similar to this to increase the number of LEDs you can control with a single microcontroller.
http://www.larwe.com/zws/products/picxie2/index.html

There are also several slave I/O expander chips available from Microchip that you can control from your microcontroller via a SPI or I2C bus that will add to the amount of I/O available.

Final option is to use SIPO (serial in parrallel out) buffer chips. This is how the large scrolling LED array signs work and should be failry simple to implement.
http://circuitlake.com/propeller-128-li ... oller.html