Getting started with the ATTiny85 and the AVR USB ISP MkII

It doesn’t take long to want to move from Arduino to more embedded uses for the Atmel MCU’s.  I got an ATTiny85 the other day and a AVR USB ISP MkII as well. Time to see if I can get the leds blinking?!

First off I had to get the Arduino IDE ready for ATTiny’s..

Installing ATtiny support in Arduino

  • Download: ATtiny (from this GitHub repository)
  • Locate your Arduino sketchbook folder ( ~/sktechbook/)
  • Create a new sub-folder called “hardware” (if it doesn’t exist already!) in the sketchbook folder.
  • Copy the attiny folder from inside the .zip to the hardware folder.
  • Restart the Arduino development environment.
  • You should see ATtiny entries in the Tools > Board menu.

Now time to wire up the ISP.. Remembering that Rst (pin 1 on the Tiny85) has to be held high via a 4K7 resister, and the ATTiny85 needs to get power from somewhere.  The ISP won’t power the circuit. No KiCAD today, just pen cad!

Pin-outs for the ISP and ATTiny85

Pin-outs for the ISP and ATTiny85

I has a RGB LED lying around so I hooked it up to the ATTiny.  Red to PWM0 (pin 5) and green to PWW1 (pin 6).

AVR USB ISP MkII connected to a ATTiny85

AVR USB ISP MkII connected to a ATTiny85

Easy and quick.. there is something very cool about a two colour pulsing LED, or is it just me?

My KiCAD version of USBtinyISP

I’m looking to make a USB AVR ISP, Eagle files are easy to find, so I thought I’d do a KiCAD version. The circuit is the same used by Ladyada, although the board is not designed to fit into the same box! I’m loving KiCAD, this took about two hours to do schematic capture and PCB layout.

USB AVR ISP - Schematic

USB AVR ISP – Schematic

PCB layout…USB AVR ISP - PCBAll the files needed are here: USB_AVR_ISP. Time to get making!