Atmel announced its 6-pin ATtiny10 MCUs in April 2009 and in late November 2009, the company introduced the ATtiny4, ATtiny5, and ATtiny9, which provide the same pin-out and functions as the ATtiny10 device. All of these MCUs include the standard AVR central processing unit (CPU). The processors all operate between 1.8 and 5.5V and they vary slightly, as noted below:
- ATtiny4: 512 bytes of Flash, 32 bytes of SRAM, one 16-bit counter/timer with a PWM channels, analog comparator.
- ATtiny5: Same as ATtiny4, but includes an ADC.
- ATtiny9: Same as ATtiny4, but with 1 kbyte of Flash.
- ATtiny10: Same as ATtiny4, but with 1 kbyte of Flash and ADC.
As you can imagine, the I/O pins get crowded. One pin carries the following designation:
That translates to a choice of:
- PCINT1:Pin Change Interrupt 0, Source 1
- TPICLK: Serial Programming Clock
- CLKI: External Clock Timer/Counter0 Input-Capture Input
- OC0B: Timer/Counter0 Compare Match B Output
- ADC1: ADC Input, Channel 1
- AIN1: Analog Comparator, Negative Input
But, what can you do with such a small MCU? Atmel noted prices for 5,000 devices start at $US 0.34 each, so the low cost should make the chip attractive in many consumer devices. An article on the Atmel Web site describes a home thermostat. I could design a smart doorbell: Press it quickly and it gives a normal ring. Press it for two seconds and it created a different ring to announce someone as a friend. Press it twice quickly and it produces a “family” ring. Even with only four I/O pins, the chip could still serve as a servo- or stepper-motor controller with a serial input.
For the 168-page manual for the ATtiny family, visit: www.atmel.com/dyn/resources/prod_documents/doc8127.pdf.
All tinyAVR microcontrollers use the standard AVR microcontroller development tools. Atmel provides its AVR Studio integrated development environment at no charge via the company Web site at: www.atmel.com/AVRStudio.
If you want to investigate the ATtiny family, Atmel offers the STK600-ATTINY10 package that contains adapter boards for the ATtiny4/5/9/10 devices. These boards plug into the STK600 starter kit and development system for the AVR and AVR32 Flash microcontrollers. –Jon Titus