Where can I Learn

how to work with the tiny cores, I've never written code for an 8 pin chip.
I would like to learn what or how much of Arduino C and C++ works and where.
Start with the header files? I built, tested and verified a set of programmers for the 13 84, 85.. Just for fun.
Any Direction?

Doc

You might already have this, but here is a link just in case:
https://code.google.com/p/arduino-tiny/downloads/detail?name=arduino-tiny-0100-0015.zip&can=2&q=

Maybe compare feature sets between the datasheets. I've read that at least some (all?) of the attinys don't have built in serial port USARTS so that leaves the hardwareSerial stuff kinda stuck.

I'm curious too as to how much of the library stuff works for the attiny.

From what I read quite a bit.. even the 85's (I bought 8 @ 1.50 Ea (no ad here) thought they'd be cute hung from a coin cell and some of "Das Blinken Lights"...
There are a whole bunch of people who have done great work... Our own Coding Badly has several very, very nice tools for the tiny cores, Tinyisp and Knock Bang and Nick Gammons really great SPI stuff and his programming pages are a must read... for Maximum Smoke.
45 years ago I got my start in commercial electronics working on 150 MHz 2 way radio's and there was a sign on the wall (of many 2 way shops too) that said "Tune For Maximum Smoke"
There is this one on the '85 http://hlt.media.mit.edu/?p=1695
and this one on the 85, Erni's page is great Communication with Tiny's and is a must because of the links and information on how to find, install and use Coding Badly's code and the links to other sites and comm protocols..
I'd Love to hang a BMP085 and a RFM12B radio on an 85, It would make a great remote Thermometer and Barometer on the 2 wire bus and one to use the DHT 22 one wire protocol and the radio to use the SPI bus. Possible to do it with the allocated pins and some hard wired decisions but what of the one wire DHT22/AMS2302 comm protocol
integer math is fine?? Wonderful

After I had written this I was reminded of my slight error.. Alas I had to come and properly state my idea's, I feel such a Fool...

Doc

Docedison:
Where can I Learn how to work with the tiny cores?

"Work with"? As in, develop an application intended to run on an ATtiny processor? As in, port an Arduino library to an ATtiny processor? As in, add support for an ATtiny processor not yet supported?

I've never written code for an 8 pin chip.

It's not much different then working with ATmega processors. Some of the differences...

• Less memory (obviously) (a few have no SRAM)

• Fewer pins (obviously)

• Fewer timers (one or two instead of three or more)

• Odd-ball timers (Atmel seems to be targeting specific applications / markets with the ATtiny processors; they created more idealized timers for those applications / markets)

• Very few have a USART

• None (few) have dedicated SPI or I2C hardware (they have a "USI" instead)

• I don't think any of them support an asynchronous timer

• Some of them have an ADC with more features

• Some have no ADC

The ATtiny84 processor is a great place to start. It's like the engine in my old Jeepster Commando: an eight cylinder engine with two cylinders chopped off. It's very similar to an ATmega328 just without timer 3.

I would like to learn what or how much of Arduino C and C++ works and where.

Everything C and C++ works. You will have problems with libraries and low-level code. Be prepared to read the datasheet.

Any Direction?

In my experience, the best place to start is with a specific project. Get some guidance on which processors would be good choices and then go to work.

Docedison:
Our own Coding Badly has several very, very nice tools for the tiny cores, Tinyisp and Knock Bang...

Thanks!

There is this one on the '85 http://hlt.media.mit.edu/?p=1695

That's the "Standard Core" with a variant for ATtiny processors. I believe the t84 and t85 are supported. I believe most / all of the problems have been resolved.

Erni's page is great...

I agree! Thank you Erni!

I'd Love to hang a BMP085...

Should work with this library...
http://code.google.com/p/arduino-tiny/wiki/TWIMasterLibrary

...and a RFM12B radio...

That should work with NewSoftSerial or maybe this...
http://arduino.cc/forum/index.php/topic,60239.0.html

...both use SPI...

Do they? It looked to me like the sensor uses I2C and the radio is essentially a simple serial port.

...and integer math is fine??

Even floating-point works.

Thank You Sir!...A lot of interesting stuff I'm about half way through your work on Erni's page for Tiny's.. I'm impressed. and reading.

Doc
Update: I looked at the tiny radio using Virtual wire and why not..I'd wanted the more sophisticated RFM12B's for uniformity and for the frequency agility and ease of changing frequency but I have 2 pairs of those boards and they are starting to look real good with the Tiny, and batteries, even coin cells look to have absurdly long lives it looks like most of my code is done, Although I do own a 3208 two panel scrolling display that would be a natural for this application as well.. display the temp RH Baro and Time/Date

Sweet.. Doc
{Edit RKJ}
I am too tired to hold my eyes open....

You are welcome.

More reading material...

http://arduino.cc/forum/index.php/topic,8553.0.html

Working notes for version 2 (and other odd-ball stuff)...
http://zygomorphic.com/arduino-tiny/

Docedison:
how to work with the tiny cores, I've never written code for an 8 pin chip.

It's exactly the same as writing code for any other Arduino.

Docedison:
I would like to learn what or how much of Arduino C and C++ works and where.

Everything works apart from hardware limitations like no USART for serial port.

Cool, I expect to have Fun. LOTS of fun.
And I'd like to take this opportunity to thank all who gave me these great links...
Especially
Coding Badly

Doc

{Edit RKJ}"Where can I Learn" Added to my Book Mark Bar, Thank You
And Each reference has 2 or 3 more links... This is GREAT...
I got the blink sketch to work on an 85 using Arduino as isp
using my hand made 23/4313 -85 Programmer.. (84 Soon too) Doc
And After the ritual Blink (with Delay) My first 85 project was a flickering candle... Nice little Chip