ATtiny Microcontrollers

The ATtiny is an extremely powerful, if small, microcontroller. The different versions range from 1kB Flash and 6 I/O lines to 16kB Flash and 18 I/O lines. The maximum clock speed is 20MHz, with most versions running 5V, and operating Vcc down to either 2.7V or 1.8V.

The ATtiny13A is an 8-pin device with 6 available for I/O. It can be used anywhere a small bit of smart is required and there just isn't any need for a more complete microcontroller solution. They are small enough and cheap enough to replace standard logic gates in some applications.

The ATtiny1634 has 18 I/O lines, and comes in QFN and SOIC packages. There is no DIP package available. It has both an 8MHz oscillator and a 32kHz oscillator onboard. Unlike other ATtiny MCU's it has two full USARTS as well as an I2C slave and the typical USI block. It also has 12 ADC channels, and one 8-bit and one 16-bit timer.

The ATtiny26A and -26L are 8-bit microcontrollers with an analog to digital converter and a PLL clock multiplier. The clock multiplier can run the high-speed timer at up to 64MHz, allowing for high speed PWM. The PWM has two non-overlapping outputs. There is no USART, but a USI with start detection easily replaces it.

The ATtiny2313 is a favorite in the ATtiny family. The ATtiny2313 has a very adequate I/O range for many applications. If more than 2k of flash is needed, the ATtiny4313 provides 4k. If you need an ADC, but not a USART, the ATtiny24 might be a better choice.

The ATtiny24/44/84 have 12 programmable I/O pins, and run off of an internal 8MHz RC oscillator. They have no USART for serial communication, but provide a USI block which can be used as a USART. 8 ADC channels and 2 timers are included as well.

The ATtiny25/45/85 has 6 programmable I/O pins, and runs off of an internal 8MHz RC oscillator, but also a 4.6MHz oscillator. It has no USART for serial communication, but provides a USI block which can be used as a USART in a pinch. 4 ADC channels and 2 8-bit timers are included as well. Pinout and functionality are similar to the ATtiny13.

The ATtinyx61 is a 20-pin device with 16 pins available for I/O. It is similar in I/O to the ATtiny26, but with the addition of pin change interrupts. It is pin-compatible. Certain peripherals can be clocked at 32 or 64MHz. One PWM uses the high-speed 8/10-bit timer to generate a true fast PWM.