Error handling in embedded projects in Arduino - Step-by-Step Execution

Concept Flow - Error handling in embedded projects

Start Program

↓

Perform Operation

↓

Check for Error?

No→Continue Normal Flow

Yes↓

Handle Error

↓

Decide: Retry or Abort?

Retry→Perform Operation

↓

Stop or Safe State

↓

End

The program runs an operation, checks for errors, handles them if found, then decides to retry or stop safely.

Execution Sample

Arduino

int sensorValue = analogRead(A0);
if(sensorValue < 0 || sensorValue > 1023) {
  Serial.println("Error: Sensor out of range");
  // handle error
}

Reads a sensor value and checks if it is outside the valid range, printing an error message if so.

Execution Table

Step	Action	sensorValue	Condition	Result	Output
1	Read sensor value	512	512 < 0 or 512 > 1023?	False
2	Continue normal flow	512	-	-
3	Read sensor value	-5	-5 < 0 or -5 > 1023?	True
4	Print error message	-5	-	Error handled	Error: Sensor out of range
5	Decide next step	-5	Retry or Abort?	Abort	Stop or safe state
6	Program ends or waits	-5	-	-

💡 Program stops or waits after handling error and deciding to abort.

Variable Tracker

Variable	Start	After Step 1	After Step 3	Final
sensorValue	undefined	512	-5	-5

Key Moments - 3 Insights

Why do we check if sensorValue is less than 0 or greater than 1023?

Because analogRead returns values between 0 and 1023; values outside this range indicate an error, as shown in execution_table step 3.

What happens if an error is detected?

The program prints an error message and then decides whether to retry or stop, as seen in execution_table steps 4 and 5.

Why might the program choose to abort instead of retrying?

To avoid endless loops or unsafe states, the program stops safely after error handling, shown in execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution table, what is sensorValue at step 3?

A -5

B 512

C 1023

D 0

💡 Hint

Check the 'sensorValue' column in execution_table row for step 3.

At which step does the program print the error message?

A Step 2

B Step 4

C Step 5

D Step 1

💡 Hint

Look at the 'Output' column in execution_table to find when the error message appears.

If sensorValue was always valid, which step would never occur?

A Step 2

B Step 1

C Step 3

D Step 6

💡 Hint

Step 3 shows the error condition; if no error, this step is skipped.

Concept Snapshot

Error handling in embedded projects:
- Check sensor or operation results for valid ranges
- If error detected, print message or signal error
- Decide to retry operation or stop safely
- Avoid infinite loops by aborting on persistent errors
- Use simple if conditions to detect errors

Full Transcript

This example shows how an embedded program reads a sensor value and checks if it is within the valid range of 0 to 1023. If the value is outside this range, it prints an error message and decides whether to retry the operation or stop safely. The execution table traces each step, showing variable values and decisions. Beginners often wonder why the range check is needed and what happens when an error occurs. The program avoids unsafe states by stopping if errors persist. This simple pattern helps embedded projects handle errors clearly and safely.