Digistump Forums

The Digispark => Digispark Project Ideas => Topic started by: psergiu on February 04, 2013, 01:32:35 pm

Title: TV Out
Post by: psergiu on February 04, 2013, 01:32:35 pm

Hi everyone.


Check-out this TV-Out lib: http://code.google.com/p/arduino-tvout/


I have tried modifying-it for Digispark, defined output pins in TVOut/spec/hardware_setup.h but got defeated by 'TIMSK1', 'TCCR2A', 'TCCR2B' and other ATMega specific variables inside the code.


Can anyone take a look ? As composite TV-out only requires 2 pins, a Digispark can easily become a PONG machine (with 2 pots).


Thank you.


PS: Is the Digispark Arduino compiling environment defining some special Digispark-related vars or only __ATtinyX5__ and __ATtiny85__ ?

Title: Re: TV Out
Post by: Bluebie on February 08, 2013, 04:14:40 pm

When making a library digispark compatible you should target attiny85 generally. If you need very specific timing, you can check F_CPU == 16500000 - however please do note this is a lie - it only runs at that speed when the digispark boots off a computer usb port. When powered externally it runs at 16.0mhz +/- 10%


I'm trying to think up a good mechanism for calibrating the digispark in the future, so it can run with a more precise clock speed even when not powered by a USB connection.

Title: Re: TV Out
Post by: semicolo on February 08, 2013, 05:51:21 pm

Couldn't the calibration value be stored somewhere (eeprom/flash) by the bootloader?

Title: Re: TV Out
Post by: Bluebie on February 09, 2013, 02:38:58 pm

That's a pretty cool idea - when the bootloader takes a program upload it could store it's calibration with the program's meta data and then when booting it could restore that if it doesn't have a chance to calibrate off USB. Cool beans!

Title: Re: TV Out
Post by: semicolo on February 10, 2013, 08:10:15 am

And another bootloader update for you  ;D ! Thanks for your dedication by the way.

Title: Re: TV Out
Post by: Rod-Singapore on April 17, 2014, 08:43:16 pm

Hi. I'm new to this but managed to do the pong game on my UNO. I would love to port the TV OUT Library but really don't know how. Anybody had figured this out???

Cheers