Legacy Circuit Mockups

Connecting Electronic Components

This guide provides step-by-step instructions for building electronic circuits on a breadboard. Each build progressively introduces new components and concepts.

Basic Component Build Instructions

Build 1 — Single LED

Components: Red LED, black jumper wire, red jumper wire, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A5 to A14.

2. Insert the red jumper wire into the breadboard from J5 to J14.

3. Place the red LED into row 14 with the positive leg (the longer of the two legs) on the right side, aligned with the red wire, and the negative leg on the left, aligned with the black wire.

4. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you insert the battery, the LED will light up.

Troubleshooting:

• Is your LED inserted backwards?

• Are the jumper wires in the same row as the LED leads?

• Are the jumper wires in the same row as the battery terminals?

Build 2 — Single Push Button

Components: Red LED, push button, black jumper wire, red jumper wire, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A5 to A16.

2. Insert the red jumper wire into the breadboard from J5 to J12.

3. Place the red LED into the breadboard with the positive leg (the longer of the two legs) inserted into H15 and the negative leg into G17.

4. Place the push button horizontally in the middle of the breadboard so the bottom-left pin is on row 16 (aligned with the black jumper wire) and the top-right pin is on row 14 (aligned with the negative leg of the red LED).

5. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you press the push button, the LED will light up.

Troubleshooting:

• Is your LED inserted backwards?

• Are the jumper wires in the same row as the LED leads?

• Are the jumper wires in the same row as the battery terminals?

Build 3 — Photoresistor-Dimmed LED

Components: Green LED, photoresistor, black jumper wire, red jumper wire, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A5 to A12.

2. Insert the red jumper wire into the breadboard from J5 to J13.

3. Place the green LED into the breadboard with the positive leg (the longer of the two legs) inserted into F13 and the negative leg into E13.

4. Insert the photoresistor into the breadboard from C12 to D13.

5. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you insert the battery, the LED will light up. Covering the photoresistor will cause the LED to dim.

Build 4 — Double LED Push Button

Components: Red LED, green LED, 220Ω resistor, push button, black jumper wire, red jumper wire, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A5 to A11.

2. Insert the red jumper wire into the breadboard from J5 to J11.

3. Insert the 220Ω resistor into the breadboard from I11 to I15.

4. Place the push button horizontally in the middle of the breadboard so the top pins are on row 15 and on opposite sides of the breadboard.

5. Place the red LED into the breadboard with the positive leg (the longer of the two legs) inserted into C17 and the negative leg into B11.

6. Place the green LED into the breadboard with the positive leg inserted into G15 and the negative leg into E11.

7. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you insert the battery, the green LED will light up. When you press the push button, the green LED will turn off and the red LED will light up.

Build 5 - Photoresistor Blinking LEDs

• Insert the black jumper wire into the breadboard from A3 to A12.

• Insert the red jumper wire into the breadboard from J3 to J12.

• Place the 555 integrated circuit chip into the middle of the breadboard with the top pins on row 12.

• Insert a jumper wire into the breadboard connecting D15 to G12.

• Insert a jumper wire into the breadboard connecting D13 to G14.

• Insert the 1000Ω resistor into the breadboard from C14 to H17.

• Insert the photoresistor into the breadboard from B14 to B15.

• Insert the capacitor into the breadboard from A13 to B12.

• Place the green LED into the breadboard with the positive leg (longer of the two legs) inserted into F17 and the negative leg into C12.

• Place the red LED into the breadboard with the positive leg inserted into I12 and the negative leg into J17.

• Insert the battery into its battery holder and place it in the breadboard, connecting negative to black and positive to red.

When you insert the battery, both LED’s will begin rapidly blinking. Covering the photoresistor from light will slow the LEDs blinking frequency.

555 Timer IC Reference

The 555 timer is a versatile integrated circuit used in timing, pulse generation, and oscillator applications. The following sections provide pinout information and internal circuit details.

555 Pinout Diagram

    ┌─────────────────────────────────────┐
    │  ●                                  │
    │  #1                             #8  │
    │  ┌──┐                         ┌──┐  │
    │  │  │                         │  │  │
    │  └──┘                         └──┘  │
    │  #2                             #7  │
    │  ┌──┐       555 TIMER         ┌──┐  │
    │  │  │                         │  │  │
    │  └──┘                         └──┘  │
    │  #3                             #6  │
    │  ┌──┐                         ┌──┐  │
    │  │  │                         │  │  │
    │  └──┘                         └──┘  │
    │  #4                             #5  │
    │  ┌──┐                         ┌──┐  │
    │  │  │                         │  │  │
    │  └──┘                         └──┘  │
    └─────────────────────────────────────┘

555 Pin Descriptions

555 Internal Block Diagram

flowchart TB
    subgraph IC["555 Timer IC"]
        direction TB

        subgraph DIVIDER["Voltage Divider"]
            R1["R (5kΩ)"]
            R2["R (5kΩ)"]
            R3["R (5kΩ)"]
            R1 --- R2 --- R3
        end

        COMP1["Comparator 1<br/>(Threshold)"]
        COMP2["Comparator 2<br/>(Trigger)"]
        FF["Flip-Flop<br/>S-R"]
        OUT_STAGE["Output<br/>Stage"]
        DISCH_TR["Discharge<br/>Transistor"]
        VREF["Vref"]
    end

    PIN8["Pin 8<br/>Vcc"] --> R1
    R3 --> PIN1["Pin 1<br/>GND"]

    R1 -.->|"2/3 Vcc"| COMP1
    R2 -.->|"1/3 Vcc"| COMP2

    PIN6["Pin 6<br/>Threshold"] --> COMP1
    PIN2["Pin 2<br/>Trigger"] --> COMP2

    COMP1 -->|R| FF
    COMP2 -->|S| FF

    FF --> OUT_STAGE
    FF --> DISCH_TR

    OUT_STAGE --> PIN3["Pin 3<br/>Output"]
    DISCH_TR --> PIN7["Pin 7<br/>Discharge"]

    PIN4["Pin 4<br/>Reset"] --> FF
    PIN5["Pin 5<br/>Control Voltage"] -.-> R2

    style PIN1 fill:#000,color:#fff
    style PIN2 fill:#f96,color:#000
    style PIN3 fill:#6f6,color:#000
    style PIN4 fill:#f66,color:#000
    style PIN5 fill:#ff6,color:#000
    style PIN6 fill:#6ff,color:#000
    style PIN7 fill:#f6f,color:#000
    style PIN8 fill:#f00,color:#fff

Build 6 — Push Button Buzzer

Components: 555 timer IC, piezo speaker, 220Ω resistor, 1000Ω resistor, capacitor, push button, jumper wires, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A1 to A11.

2. Insert the red jumper wire into the breadboard from J1 to J11.

3. Place the 555 integrated circuit chip into the middle of the breadboard with the top pins on row 11.

4. Insert a jumper wire into the breadboard connecting D12 to G13.

5. Insert a jumper wire into the breadboard connecting D14 to G11.

6. Insert the capacitor into the breadboard from A12 to B11.

7. Insert the 220Ω resistor into the breadboard from C12 to C13.

8. Place the push button horizontally in the middle of the breadboard so the top pins are on row 15 and on opposite sides of the breadboard.

9. Insert the piezo speaker into the breadboard with the positive pin in A9 and the negative pin in A6.

10. Insert the 1000Ω resistor into the breadboard from E6 to A13.

11. Insert a jumper wire into the breadboard connecting C9 to D15.

12. Insert a jumper wire into the breadboard connecting G17 to I11.

13. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you press the push button, the buzzer will sound.

Build 7 — Photoresistor Theremin

Components: 555 timer IC, piezo speaker, photoresistor, 1000Ω resistor, capacitor, push button, jumper wires, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A1 to A11.

2. Insert the red jumper wire into the breadboard from J1 to J11.

3. Place the 555 integrated circuit chip into the middle of the breadboard with the top pins on row 11.

4. Insert a jumper wire into the breadboard connecting D12 to G13.

5. Insert a jumper wire into the breadboard connecting D14 to G11.

6. Insert the capacitor into the breadboard from A12 to B11.

7. Insert the photoresistor into the breadboard from C12 to C13.

8. Place the push button horizontally in the middle of the breadboard so the top pins are on row 15 and on opposite sides of the breadboard.

9. Insert the piezo speaker into the breadboard with the positive pin in A9 and the negative pin in A6.

10. Insert the 1000Ω resistor into the breadboard from E6 to A13.

11. Insert a jumper wire into the breadboard connecting C9 to D15.

12. Insert a jumper wire into the breadboard connecting G17 to I11.

13. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you press the push button, the buzzer will sound. Covering the photoresistor will change the pitch of the buzzer.

Build 8 — Potentiometer-Dimmed LED

Components: Green LED, potentiometer, 220Ω resistor, black jumper wire, red jumper wire, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A1 to A13.

2. Insert the red jumper wire into the breadboard from J1 to J9.

3. Place the potentiometer with the two-pin side on the left, top pin in E13 and bottom pin in E15.

4. Insert the 220Ω resistor into the breadboard from H9 to H14.

5. Place the green LED into the breadboard with the positive leg (the longer of the two legs) inserted into C15 and the negative leg in B13.

6. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: When you insert the battery, the LED will turn on. Rotating the potentiometer will increase or decrease the brightness of the LED.

Build 9 — Push Button RGB LED

Components: RGB LED (common cathode), three push buttons, two 220Ω resistors, black jumper wire, red jumper wire, jumper wires, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A1 to B7.

2. Insert the red jumper wire into the breadboard from J1 to J7.

3. Insert the RGB LED into the breadboard from A4 to A8. The longest of the four legs is the ground and should be in A7.

4. Place three push buttons horizontally in the middle of the breadboard with pins at:

   • Button 1: E9–F9 and E11–F11

   • Button 2: E12–F12 and E14–F14

   • Button 3: E15–F15 and E17–F17

5. Insert a jumper wire into the breadboard connecting C5 to D9.

6. Insert a jumper wire into the breadboard connecting C6 to C12.

7. Insert a jumper wire into the breadboard connecting B8 to B15.

8. Insert the first 220Ω resistor into the breadboard from G7 to G11.

9. Insert the second 220Ω resistor into the breadboard from H7 to H14.

10. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: Pressing each push button will activate a different color channel of the RGB LED.

Build 10 — Potentiometer-Controlled Buzzer

Components: 555 timer IC, piezo speaker, potentiometer, 220Ω resistor, capacitor, push button, jumper wires, battery with holder

Steps:

1. Insert the black jumper wire into the breadboard from A1 to A11.

2. Insert the red jumper wire into the breadboard from J1 to J11.

3. Place the 555 integrated circuit chip into the middle of the breadboard with the top pins on row 11.

4. Insert a jumper wire into the breadboard connecting D12 to G13.

5. Insert a jumper wire into the breadboard connecting D14 to G11.

6. Insert the capacitor into the breadboard from A12 to B11.

7. Insert the piezo speaker into the breadboard from A6 to A9 (place the positive end on the bottom).

8. Place the push button horizontally in the middle of the breadboard so the top pins are in E15 and F15.

9. Insert the 220Ω resistor into the breadboard from E6 to A13.

10. Insert a jumper wire into the breadboard connecting E9 to D15.

11. Insert a jumper wire into the breadboard connecting G17 to I11.

12. Place the potentiometer with the two-pin side on the right, top pin in F7 and bottom pin in F9.

13. Insert a jumper wire into the breadboard connecting D8 to B13.

14. Insert a jumper wire into the breadboard connecting H7 to C12.

15. Insert a jumper wire into the breadboard connecting H9 to D11.

16. Insert the battery into its holder and place it in the breadboard, connecting negative to black and positive to red.

Result: Pressing the push button will cause the buzzer to sound. Rotating the potentiometer will alter the pitch of the buzzer.