Materials for the clock module
The build is designed to be made on a 1/4 size solderable breadboard (17 holes wide, 10 tall) with tracks. Like this:
Components
- C1: 1 µF (timing capacitor)
- C2: 0.1 µF (decoupling capacitor)
- R1: 1 KΩ (discharge resistor)
- R2: 1 KΩ (charge resistor)
- 3 x RP: 10 KΩ (pull-up/pull-down resistors)
- 3 x RL: 330 Ω (LED protection. You can change this if you like your LEDs brighter/dimmer)
- LED: blue 5mm LED (clock output indicator. You can use a 3mm if you prefer)
- 2 x LEDI: green 3mm LED (mode indicator)
- POT: 1 MΩ linear potentiometer (speed control. Make sure it’s not too bulky; space is tight)
- BUT: push button, normally open (single-step button)
- SWI: SPDT switch, 3 inline pins. (mode selector. Make sure it’s a narrow one to fit the allocated place)
- J1 (CLK): 4-way, single-row PCB socket (connector for clock output. It’s convenient to have a multiway connector to attach to multiple circuits, but you can do with less ways if you prefer).
- J2 (HLT/GND): 2-way, single-row PCB socket (connector for GND and HLT lines)
- J3 (VCC): 2-way, single-row PCB socket (connector for VCC. if you get a 1-way it may be easier to place, but I couldn’t find those).
- U1: 555 (timer IC)
- U2: ATF16V8B (Simple programmable logic device)
- a DIP-20 socket for U2 (not required, but strongly recommended)
- some jumper wires
Here’s a picture of everything labelled:
I’ve added some nylon “legs” which are M2 nylon spacers + nylon nuts; but the size of those may depend on the specific solderable board you use. Those are entirely optional.