Hello, question.
Looking to take 10 2mm LEDs, 5 will burn steady, 5 will randomly fade in and out using LED flasher. Wanted to run it all off the ATTiny85 chip. 5 steadies are fine - simple digitalwrite and i can use pin 2, 3. or 7 for that.
But only 5 and 6 can do PWM. Can i chain those other 5 on just one PWM pin, or will they all fade in and out together? Looking for each of those five to fade randomly from each other.
I don't know the pins on that controller but here's a try.
Connect some cathods to digital outputs and the anodes to the PWM pins. Of course one serie resistor per LED is needed.
Activating a LED is done writing a LOW to the digital output.
Lots of words from the tablet...
10 LEDs from only 6 outputs, how is that going to work?
Do you actually mean an ATTiny84 chip?
Not sure what this means but it is nonsense.
Then you write a state machine, like the blink without delay example in the IDE but have the blinking fast so it looks like PWM.
Each "task" will have its own time that it has to execute in, and you can change that time depending on if you just turned the LED on or off.
With Charlieplexing you should be able to drive many leds from only a few pins.
Can you post a link to the specs of these LEDs?
You could do those things you want with ws2812/apa106 LEDs. All 10 LEDs can be chained off 1 pin and can fade independently or stay lit as you choose. But those LEDs are not 2mm.
You don't need to use any pin for that. Just connect the LEDs across 5V and ground, each with a series resistor.
Yes, they would all fade together. You would need to either use high value series resistors or a transistor to avoid damaging the pin with too much current.
Yes, thanks. I realized that after I typed it. And that being the case, that leaves 5 pins. Only two need to fade, so the two PWMs would work fine, and I can just blink the other 3.
Just use a bigger processor
If you use this core, you will have 3 PWM pins (4, 5, 6):
You can "bit bang" more PWM pins in your sketch, but it is tricky for a beginner.