DuaneB:
Sorry for a dumb question, but having a look on the Atmel site, there are dozens of Attiny chips,
It is not a dumb question. Other than very basic information (e.g. Flash and SRAM) size, Atmel's website is woefully lacking in marketing information (e.g. "what cool things does this processor have that the others do not").
what are or where can I find the major difference between the Families 84,85 and 2313 ?
Timer 0 is identical across all the processors.
85
It has enough memory to support complicated / multipurpose applications (8K Flash, 512 SRAM). It has two siblings (45 and 25) that are identical except memory sizes. You would use a smaller sibling if cost is a concern and you know your application will fit.
The 85 processor is an 8 pin chip: 5 I/O pins, RESET, power and ground.
The analog-to-digital converter is very similar to the one on the 328 processor. The ADC has a few more features: 2.56V reference, differential inputs.
The 85 processor can be easily configured to run at 1 MHz, 8 MHz, and 16 MHz with no external components. It can be driven from an external crystal or resonator.
Timer 1 is a PWM beast: optional 64 MHz base frequency, plethora of prescalers, inverted outputs, dead-time generator.
For SPI and I2C communcations the processor has a "USI – Universal Serial Interface". The USI is a very simplified version of the hardware available on a 328.
84
It has enough memory to support complicated / multipurpose applications (8K Flash, 512 SRAM). It has two siblings (44 and 24) that are identical except memory sizes. You would use a smaller sibling if cost is a concern and you know your application will fit.
The 84 processor is a 14 pin chip: 11 I/O pins, RESET, power and ground.
The analog-to-digital converter is very similar to the one on the 328 processor. The ADC has more features: differential inputs, selectable 20x gain.
The 84 processor can be easily configured to run at 1 MHz and 8 MHz with no external components. It can be driven from an external crystal or resonator.
Timer 1 is essentially identical to timer 1 on the 328.
For SPI and I2C communcations the processor has a "USI – Universal Serial Interface". The USI a very simplified version of the hardware available on a 328.
2313
It has very little memory (2K Flash, 128 SRAM). The 2313 has a bigger brother (4313) that is identical except memory size (4K, 256).
The 2313 processor is a 20 pin chip: 17 I/O pins, RESET, power and ground.
It has a USART similar to the one on the 328 (including Multi-processor Communication mode).
An analog-to-digital converter does not exist.
The 2313 processor can be easily configured to run at 1 MHz and 8 MHz with no external components. It can be driven from an external crystal or resonator.
Timer 1 is essentially identical to timer 1 on the 328.
For SPI and I2C communcations the processor has a "USI – Universal Serial Interface". The USI is a very simplified version of the hardware available on a 328.