Task: Program your ATTiny85 chip with micronucleus firmware: https://github.com/embedded-creations/micronucleus-t85. 

You should have Arduino installed on your system.

Using an Arduino as ISP, wire up the ATTiny85 chip for programming. You have two options to do this:

• You can do this for an SMD ATTiny85 by using a breakout board. Adafruit sells these. NOTE THAT YOU WILL NEED TO DESOLDER. I found the best way is to use a hot-air gun for desoldering.
• You can also directly solder the ATTiny85 onto the board and wire up the board to the ISP the vias using anything above a 24 gauge wire.

VCC->5V  
PB5->10  
PB2->13  
PB1->12  
PB0->11  
GND->GND   

Run the following code to upload (edit the green code to the path of the micronucleus hex file):

avrdude -c arduino -p t85 -b 19200 -P /dev/ttyACM0 -U flash:w:'.../t85_default.hex' -U lfuse:w:0xe1:m -U efuse:w:0xfe:m -U hfuse:w:0xdd:m

 Upgrade the micronucleus firmware to micronucleus-1.06-jumper-v2-upgrade.hex. I used an old Digispark that had a desoldered ATTiny85 and wired up the newly programmed ATTiny85 to its breakout pins it so that I could communicate over USB. Once connected, I ran the upgrade hex over micronucleus to remove the 5 second delay.

micronucleus --run 'micronucleus-1.11-entry-jumper-pb0-upgrade.hex'

Upload the code for the BreatheDot after the micronucleus firmware has been loaded by grounding Pin 0 on the ATTiny85, and uploading the code through Arduino.

You can also program it over the Arduino ISP by running the same code but changing the path of the file. Remove the lines to set the fuses:

avrdude -c arduino -p t85 -b 19200 -P /dev/ttyACM0 -U flash:w:'program.hex' -U lfuse:w:0xe1:m -U efuse:w:0xfe:m -U hfuse:w:0xdd:m

Upload the final code for the program by exporting the code as a hex file and uploading it via the Arduino ISP.

Solder all parts on board. Parts list is provided as part of project description. You will need a 1k resistor for the soldering pad near the LED, which should be centered on the board, and a 0.1uF capacitor for one of the soldering pads near the ATTiny85. If your LED doesn't light up, try changing the orientation of the LED. Remember to align the ATTiny85 to the silkscreen.

1. Test PWR and GND pins are not touching.
2. Test PWR is connected to VCC line when switch is turned on
3. Test VCC is touching the VCC pin on the ATTiny85
4. Check no pins are touching
5. Check that LED is soldered in the right direction