some led sequencing help

rajun_cajun

hello i am new to this thing and i bought one of the microcontrollers now i am trying to make some tail lights for my car but i want to display differnt things over them like when i hit the brake it will say SS or when i hit the turn it will sequence across the display and maybe some other things but is this the right tool to do this i have been reading and playing around with it but i realy am not seeing how to do what i need to do also how many diffrent leds can i control with this kit just the 15 that is on the board or can i add more to it

thanks for your help

SRLM

You can control more in several ways. Probably the easiest would be to use a Darlington array chip, and tie one of the outputs over to the inputs of the other 7 or so. This would allow you to drive 112 LEDs in a total of 16 groups. Of course, the effective count is lower since you need an input or two. So, there are I/O expander chips available, and special LED I/O expander chips too I believe. As for input, you'll have to figure out how you can sense when the brake is pressed/turn signal is on. You might be able to get it done by simply cutting the wires off the current lights and treating it as a digital high/low. Of course, you'll need to reduce the voltage from 12 v to 5v for this, and you'd have to retain the blinking on the turn signal.

PJAllen

http://forums.parallax.com/showthread.php?p=726483

rajun_cajun

thats fine is kinda what i am trying to do but that is only with three lights on driver side and three lights on pass side i am looking at a row of 6 leds cus i only have 12v and a row of 6 leds in parallel to them and something like 25 30 rows long i just will like to make it do things like chase over all of them maybe shoot arrows across them also maybe display ss on them the brake is not a problem i have got that part but the turn swich is what i really am trying to do

thanks everyone for your help