Hi, I have a sketch which illuminates an LED and uses PWM to fade it out. It works properly on an Arduino Uno, but on an ATtiny85 (via the HLT core) the LED switches off before it's fully faded. I was wondering if anyone can speculate as to why the fade behaves differently on the Attiny85. Strange…

Sure! /* The purpose of this sketch is to immediately illuminate LEDs when it detects sound over a certain threshold. The LEDs will stay on for a fixed time, then fade out. The cycle will start any time a sound peak is detected. 5/17/11 - The sketch functions as intended. */ // User set variabl…

via the HLT core Previously you had been using the Arduino Tiny Core. If you still have the Tiny Core installed, try using it. Does this fade the LED? void setup( void ) { pinMode( 1, OUTPUT ); } void loop( void ) { for ( int i=0; i <= 255; ++i ) { analogWrite( 1, i ); delay( 10 …

I'll see if I can replicate your issues when I get home if I can steal some time. I've been looking for something to poke and prod!

Ok, a few things have shown up. For one, there is no analog input #4, so analogRead(4) returns 0, or at least not a reasonable value (for me, at least!). Moving the mic pin to 3 and the threshhold to 2 fixed that issue. I think what you're running into is that your fading and your ending the fade…

Finally had some time to pick this back up again. Your Tiny Core has done the trick! It now fades out nice and smoothly, and for the most part my sketch seems to run properly. I guess all cores are not created equal. A massive thanks for providing your Tiny Core! Would your core also allow me to pr…

Given that an LED doesn't produce audio noise (well, it can once if you drive it hard enough :P) you're almost certainly seeing electrical noise. Do you have 10-100uF and 0.1uF caps on the VCC line right next to the MCU? I don't know if op-amps need such things as well, never used an op-amp. I di…

Your Tiny Core has done the trick! A massive thanks for providing your Tiny Core! Excellent. I'm glad it worked well for you. You are welcome. Would your core also allow me to program the SOIC version of the ATtiny85, using the same method as the DIP version? Should be exactly the same. As fa…

Bobnova: Given that an LED doesn't produce audio noise (well, it can once if you drive it hard enough :P) you're almost certainly seeing electrical noise. Do you have 10-100uF and 0.1uF caps on the VCC line right next to the MCU? I don't know if op-amps need such things as well, never used an op…

AnalogRead is the only thing the ADC can be used for, without smoothing on it you can get some interesting spikes (which may be triggering your issues, who knows). I did indeed test with a piezo speaker acting as a microphone, it works pretty well though I'm sure a microphone+opamp is a lot more se…

Attiny85 fade problem

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CrossRoads August 24, 2011, 5:23pm 2

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Attiny85 fade problem

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