ATTiny85
Posted: Thu Oct 11, 2018 9:24 pm
I've been trying to get an ATTiny85 to drive a WS2812 LED strip without much success. (I got it to work for ~10 LEDs)
It seems the timing is a bit out - the Adafruit library puts out a ~812kHz - but using Flowcode I'm just getting ~750kHz - looking at the output on an oscilloscope.
Has anyone got an ATTiny up and running with this component?
The ATTiny 'should' be running at 16MHz - but there isn't an option to in the Project Options - configure tab for this.. (This is a confusing list of dozens of options - however because the selection box isn't wide enough to display all the text, it isn't easy to make an informed decision here? - on selecting an option the text box of the Configure tab is also too short to display all the text - resizing the dialog box doesn't help).
Setting the clock to 16MHz and trying various settings wasn't successful - the WS2812s may not be as demanding on timing as advertised - (see for example https://wp.josh.com/2014/05/13/ws2812-n ... #more-1681 - he also has some great ideas for large (very large) displays driven by an Arduino - by not buffering the strip contents)
Is there a better option to upload the program to the 85? I'm using a digispark board running a micronucleus kernel - which allows programming via USB... Flowcode tries to use AVRDude via a usbtiny which I'm not using. I'm currently using the digistump tools via the command line - but it's not a particularly smooth process - I keep closing the cmd window by mistake (aaarrggh)
Why - I had an idea to try a POV 'fan' - and initially thought - port expander and ATTiny85 (which I wanted to try) - but then the appeal of RGB at each point got to me and I decided to try a short string of addressable LEDS (and anything that reduces the amount of soldering & wiring appeals big time too ) - this might not be fast enough for a good POV display ???
Martin
It seems the timing is a bit out - the Adafruit library puts out a ~812kHz - but using Flowcode I'm just getting ~750kHz - looking at the output on an oscilloscope.
Has anyone got an ATTiny up and running with this component?
The ATTiny 'should' be running at 16MHz - but there isn't an option to in the Project Options - configure tab for this.. (This is a confusing list of dozens of options - however because the selection box isn't wide enough to display all the text, it isn't easy to make an informed decision here? - on selecting an option the text box of the Configure tab is also too short to display all the text - resizing the dialog box doesn't help).
Setting the clock to 16MHz and trying various settings wasn't successful - the WS2812s may not be as demanding on timing as advertised - (see for example https://wp.josh.com/2014/05/13/ws2812-n ... #more-1681 - he also has some great ideas for large (very large) displays driven by an Arduino - by not buffering the strip contents)
Is there a better option to upload the program to the 85? I'm using a digispark board running a micronucleus kernel - which allows programming via USB... Flowcode tries to use AVRDude via a usbtiny which I'm not using. I'm currently using the digistump tools via the command line - but it's not a particularly smooth process - I keep closing the cmd window by mistake (aaarrggh)
Why - I had an idea to try a POV 'fan' - and initially thought - port expander and ATTiny85 (which I wanted to try) - but then the appeal of RGB at each point got to me and I decided to try a short string of addressable LEDS (and anything that reduces the amount of soldering & wiring appeals big time too ) - this might not be fast enough for a good POV display ???
Martin