Soldering 101

Intro to through-hole soldering

We will solder a blinking, customizable name tag. We will also discuss and explain the design and the theory of operation.

Circuit

• A discrete astable BJT multivibrator feeding into a 74HC595 shift register, which drives the LEDs directly.
• The shift register can serve up to 8 segments.
• The LED matrix can partitioned arbitrarily column-wise: multiple columns can be grouped onto a single counter output.
• each shift register output has one series current limiting resistor
• multiple display modes:
  • blink (CLK goes into enable)
  • fill slowly, clear slowly (last output inverted feeds back)
  • fill slowly, clear at once (last output inverted goes to reset)
  • rotate (last output feeds back)
• multivibrator speed can be adjusted with a pot
• on/off switch?

Components

• LED, $0.04650 @ 1000: http://search.digikey.com/us/en/products/WP710A10SRD%2FD/754-1593-ND/2769819
• 74HC595N,112, $0.378 @ 100: http://search.digikey.com/us/en/products/74HC595N,112/568-1484-5-ND/763088
• CR2032 holder, $0.4968 @ 100: http://search.digikey.com/us/en/products/3003/3003K-ND/227448
• Pushbutton, $0.0916 @ 100: http://search.digikey.com/us/en/products/FSM4JH/450-1650-ND/1632536
• Pot, $0.3197 @ 100: http://search.digikey.com/us/en/products/3306P-1-105/3306P-105-ND/84994
• PCB 5cm x 10cm, $1.498 @ 50: http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html