Step $2$: Upload the Code

Upload the following partial code to the Arduino IDE and edit to include math functions:

void setup$()\{$

$$ Serial.begin$(9600)$; $//$ Start Serial communication

$$ Serial.println$("$Welcome to the Arduino Math Lab!"$)$;

$$ Serial.println$("$Commands:$")$;

$$ Serial.println$("$ ADD x y $-$ Add two numbers"$)$;

$$ Serial.println$("$ SUB x y $-$ Subtract two numbers"$)$;

$$ Serial.println$("$ MUL x y $-$ Multiply two numbers"$)$;

$$ Serial.println$("$ DIV x y $-$ Divide two numbers"$)$;

$$ Serial.println$("$Type your command:"$)$;

$\}$

$$

void loop$()\{$

$$ if $($Serial$.$available$()>0)\{$

$$ String input $=$ Serial.readStringUntil$(\text{'}$

$\text{'})$; $//$ Read input from Serial Monitor

$$ input.trim$()$; $//$ Remove any whitespace or newline characters

$$ processInput$($input$)$; $//$ Process the command

$\}$

$\}$

$$

void processInput$($String input$)\{$

$//$ Split the input into command and arguments

$$ String command $=$ input.substring$(0,$ input.indexOf$(\text{'}\text{'}))$;

$$

$$

$$

$$

String args $=$ input.substring$($input$.$indexOf$(\text{'}\text{'})+1)$;

$$

$$

$//$ Extract numbers from the arguments

$$ int firstSpace $=$ args.indexOf$(\text{'}\text{'})$;

$$

$$

$$

$$

if $($firstSpace $==-1)\{$

$$ Serial.println$("$Invalid command format. Use: CMD x y$")$;

$$ return;

$\}$

$$

$$

$$ String num$1$Str $=$ args.substring$(0,$ firstSpace$)$;

$$ String num$2$Str $=$ args.substring$($firstSpace $+1)$;

$$

$$

$$

$$ float num$1=$ num$1$Str$.$toFloat$()$;

$$ float num$2=$ num$2$Str$.$toFloat$()$;

$$

$//$ Execute the math command

$$

$$ if $($command $==$ "ADD"$)\{$

$$

$//$CODE HERE

$\}$

else if $($command $=="???")\{$

$$

$//$CODE HERE

$\}$

$$

$//$add additional commands here

$$

else $\{$

$//$CODE HERE$\}$

$\}$

$$

else $\{$

$$ Serial.println$("$Unknown command. Please use ADD, SUB, MUL, or DIV."$)$;

$\}$

$$ Serial.println$("$Commands:$")$;

$$ Serial.println$("$ ADD x y $-$ Add two numbers"$)$;

$$ Serial.println$("$ SUB x y $-$ Subtract two numbers"$)$;

$$ Serial.println$("$ MUL x y $-$ Multiply two numbers"$)$;

$$ Serial.println$("$ DIV x y $-$ Divide two numbers"$)$;

$$

$\}$

Step $3$: Run the Program

Open the Serial Monitor in the Arduino IDE $($Ctrl $+$ Shift $+$ M$).$

Set the baud rate to $9600.$

Enter commands in the Serial Monitor in the following format:

ADD $53$ to add $5$ and $3.$ SUB $104$ to subtract $4$ from $10.$ MUL $78$ to multiply $7$ and $8.$ DIV $204$ to divide $20$ by $4.$

Tasks:

Task $1$: Perform Basic Math Operations

Use the Serial Monitor to perform:

Addition of two numbers $($e$.$g$.,$ ADD $1510).$ Subtraction of two numbers $($e$.$g$.,$ SUB $205).$ Multiplication of two numbers $($e$.$g$.,$ MUL $46).$ Division of two numbers $($e$.$g$.,$ DIV $183).$

Observe the results printed on the Serial Monitor.

Task $2$: Handle Edge Cases

Try dividing a number by zero $($e$.$g$.,$ DIV $100)$ and observe the error message.

Enter invalid commands $($e$.$g$.,$ XYZ $55)$ or incomplete inputs $($e$.$g$.,$ ADD $5)$ and observe the program's response.

Task $3$: Modify the Code

Add a new math operation $($e$.$g$.,$ modulus MOD to calculate remainders$).$

Test your modification by entering commands like MOD $103.$

Expected Output

When entering ADD $73,$ the Serial Monitor should display:

Result: $10$

When entering DIV $80,$ the Serial Monitor should display:

Error: Division by zero is undefined.

For invalid input like XYZ $55,$ the Serial Monitor should display:

Unknown command. Please use ADD, SUB, MUL, or DIV.

Discussion Questions

How does the program parse and extract numbers from the input string?

Why is trim$()$ used on the input string?

What happens if the user enters invalid input, and how can this be improved?

Assessment

Successfully perform all four math operations.

Demonstrate how the program handles edge cases.

Modify the code to include a new math function.

Key Takeaways

You should gain hands$-$on experience with Serial Monitor input$/$output$.$

Understand the use of strings, parsing, and basic error handling in Arduino programming.

Explore the versatility of Arduino in performing computational tasks.