Hello Grumpy_Mike-
thanks for the reply..
re: shift registers-
not essential.. ifyou wanted to drive/have more leds that you have I/O pins available.. then needed yes? or are you saying you can add more leds on 1 i?o pin of the Arduino?
In CorssRoads post..
he mentions using 4 pins (each) for Anode and cathode
4 arduino outputs go to current limit resistors to the 4 anodes. Values selected so that 8mA can flow.
4 arduino outputs go to the cathodes.
which essentially takes up 8 pins of the Arduino.. yes?
giving me a total of only 16 leds though.. yes?
ie: 2 leds per Arduino I/O pin?
for each row or column.. there needs to be another I/O pin on the Arduino used.. correct?
if you were using only 2 Arduino PWM output pins (1 for resistor >> anode) and (1 or cathode).. you could only have 2 leds...correct?
So in this project/theory.. you would need to use a shift register chip....yes? (which Im not against... except now I read you called it babyish!) LOL..
which by that I think your saying not the best/most professional approach? (for actually driving/powering the leds?..how would you otherwise do it? with that many leds?) space IS a concern... would these drivers be needed for each led? or segment of led array?
sorry totally clueless about how one would go about wiring this all up?
my project will involve ALOT of LEDS.. IMHO..if I had to guess.. Id say 2 x separate strings of 40 leds each.. (80 total?)
these would be HB SMD leds.. (1206 footprint/package)....
not sure yet though.. might just be an odd 4mm HB oval leds I have laying around too)
Im assuming this is way to much for the Arduino to handle by itself....and would require an 'shift register'...?
thanks
Are there other (small) shift register chips out there besides the: 74HC595 that only gives (I think) 8 outputs for leds?