Eras of Blinking

Blinking an LED as it was done in the 1970s (555) and the 1990s (AVR).

I am using this project to learn KiCAD and SMT fabrication. Also learning to use pogo pins to flash a microcontroller.

The ISP Pogo Jig

I designed and built a jig to hold pogo pins against the board's ISP headers to program the AVR. In the end, I did not use the jig; it did not press the pogo pins against the contacts hard enough to make a solid connection.

I found Nick Sayers' AVR ISP Pogo Adapter v0.5 on OSH Park and ordered it. I soldered the pogo pins to two boards 7 mm apart so the pins would be well aligned.

I use ecad.io to create STEP files representing the boards' geometric shapes. I imported the boards into Fusion 360, modeled a pogo pin, and designed a jig around them.

The Fusion 360 model is here.

If I did it again, I would do it very differently. I think I would flip the jig over so the board sits on top, with some kind of latch to hold it in place.

Differences between v1.0 and v1.1

• Shrink through holes for battery clip.
• Eliminate rectangle around "AVR" lettering.
• Change "555" and "1971" lettering to get better separation.
• Enlarge "CR2032" lettering.
• Enlarge presidents' caricatures, just keep the faces.
• Increment the silkscreen version number.

Resources

Getting to Blinky 4.0 Video tutorials for KiCAD 4.0

Flashing LED Circuit Simple 555 astable circuit. Cribbed mercilessly.

How to Build an AVR Blinking LED Circuit

Programming an ATtiny w/ Arduino 1.6

LED Resistor Calculator

3D KiCAD Parts tutorial

KiCAD graphics tutorial