1. Logic Gates Practical
Objective: to develop an understanding of logic circuits and truth tables.

2. Symbols Recap
Each logic gate is represented by a different symbol.

3. Components Logic Gate Output Input 1 Input 2 Output Change Gate Button

4. Truth Tables
We use truth tables to show all the different possible states of a logic circuit.
This is partially complete truth table for a NOT gate logic circuit. It shows all the possible inputs.
Input
Output 1

5. Activity 1a
Create this logic circuit:

6. Activity 1b
Ensure your logic gate is set to be a NOT gate by pressing the A button on the micro:bit.
Use your logic circuit to help you complete the truth table for a NOT gate:
Input
Output 1

7. Activity 2a
Add another switch to your circuit as shown below:

8. Activity 2b
Ensure your logic gate is set to be an AND gate by pressing the A button on the micro:bit.
Use your logic circuit to help you complete the truth table for an AND gate:
Input 1
Input 2
Output 1

9. Activity 2c
Ensure your logic gate is set to be an OR gate by pressing the A button on the micro:bit.
Use your logic circuit to help you complete the truth table for an OR gate:
Input 1
Input 2
Output

10. Activity 3a
Add another logic gate to your circuit as shown below:

11. Activity 3b
Ensure logic gate 1 is set to be a NOT gate and logic gate 2 is set to be an AND gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Output

12. Activity 3c
Ensure logic gate 1 is set to be a NOT gate and logic gate 2 is set to be an OR gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Output

13. Activity 4a
Change your logic circuit as shown below:

14. Activity 4b
Ensure logic gate 1 is set to be an AND gate and logic gate 2 is set to be a NOT gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Output

15. Activity 4c
Ensure logic gate 1 is set to be an OR gate and logic gate 2 is set to be a NOT gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Output

16. Activity 5a
Add another switch to your logic circuit as shown below:

17. Activity 5b
Ensure logic gate 1 is set to be an AND gate and logic gate 2 is set to be an OR gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Input 3
Output 1

18. Activity 5c
Ensure logic gate 1 is set to be an OR gate and logic gate 2 is set to be an AND gate.
Use your logic circuit to help you complete the truth table for the circuit:
Input 1
Input 2
Input 3
Output