Prototype a VL53L0X range decision in Wokwi

Exercise a VL53L0X firmware decision path with an explicit Wokwi range-input surrogate and compare it with one HC-SR04 line without claiming physical-sensor evidence.

Radio Remi: compare the two readings, then state exactly what the simulator did not test., your practice guide

Radio Remi: compare the two readings, then state exactly what the simulator did not test.
Predict the reading, then compare it with the measurement.

Wokwi ESP32

Third party Tool

Exercise a VL53L0X firmware decision path with an explicit Wokwi range-input surrogate and compare it with one HC-SR04 line without claiming physical-sensor evidence.

Tier 1 · Web · No account

Version tested: Wokwi browser simulator and CLI 0.21.1; ESP32 core 3.3.11; Chromium 148.0.7778.96; captureSource playwright:wokwi; captured in the Wokwi web editor on 2026-09-10. Date: 2026-09-10.

Open the ESP32 editor, paste diagram.json, then paste sketch.ino.

Open Wokwi to paste in the files (new tab)

Get the files

Use both prepared files. This is a paste-in setup; saving a project requires a Wokwi account.

diagram.json

740 bytes · Circuit connections

Download

sketch.ino

1,129 bytes · ESP32 program

Download

// Wokwi's supported-parts catalogue does not currently contain a VL53L0X.
// This potentiometer is an explicit range-input surrogate for the firmware
// decision path. Replace readTofMm() with the vendor driver on real hardware.
const int TOF_SURROGATE_PIN = 34;
const int TRIG_PIN = 18;
const int ECHO_PIN = 19;

float ultrasonicCm() {
  digitalWrite(TRIG_PIN, LOW); delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  unsigned long pulse = pulseIn(ECHO_PIN, HIGH, 30000);
  return pulse ? pulse / 58.0 : -1.0;
}

int readTofMm() {
  int raw = analogRead(TOF_SURROGATE_PIN);
  return map(raw, 0, 4095, 50, 2000);
}

void setup() {
  Serial.begin(115200);
  pinMode(TOF_SURROGATE_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.println("RANGING READY: VL53L0X range-input surrogate; not a stopping-safety test");
}

void loop() {
  int tofMm = readTofMm();
  float soundCm = ultrasonicCm();
  Serial.printf("ToF surrogate=%d mm status=SIM | HC-SR04=%.1f cm (different beam and physics)\n",
                tofMm, soundCm);
  delay(800);
}

Use the launch button above to open the ESP32 editor in Wokwi.
Select the editor’s diagram.json tab and replace all its text with the supplied diagram.json.
Select the sketch.ino tab, replace all its text with the supplied sketch.ino, then click Start Simulation.

Steps

Screens captured against Wokwi ESP32 Wokwi browser simulator and CLI 0.21.1; ESP32 core 3.3.11; Chromium 148.0.7778.96; captureSource playwright:wokwi; captured in the Wokwi web editor on 2026-09-10 on 2026-09-10; the tool may have moved on — the text steps are the contract.

Step 1
Do
In diagram.json, identify the labelled optical-range surrogate and the HC-SR04 trigger and echo wiring.
You will see
The ESP32 reads a controlled range input on GPIO 34 and a simulated ultrasonic pulse path on GPIO 18 and 19.
Why it matters
Wokwi currently lacks a VL53L0X part, so the surrogate tests only the range-decision path; a physical module would use I2C.
Step 2
Do
In sketch.ino, find the surrogate boundary, millimetre conversion, and ultrasonic comparison line.
You will see
The code labels simulated optical status and ultrasonic centimetres separately.
Why it matters
Firmware should keep source, status, units, and plausible bounds visible before acting.
Step 3
Do
Start the Wokwi simulation and open Serial Monitor.
You will see
Serial Monitor prints RANGING READY and names the surrogate before the first sample.
Why it matters
The lab changes a bounded range input and prints millimetres beside one HC-SR04 comparison line.
Step 4
Do
Leave the optical-range control near 200 mm and the ultrasonic target at 100 cm.
You will see
A line reports about 200 mm for the ToF surrogate and 100 cm for HC-SR04.
Why it matters
Holding one target fixed makes the units and paths visible before a change.
Step 5
Do
Turn the labelled VL53L0X range-input control to the prepared 500 mm fixture.
You will see
The next surrogate line changes to about 500 mm while HC-SR04 stays near 100 cm.
Why it matters
Changing one input at a time exposes which reading the control affects.
Step 6
Do
Restart and read the declared safety boundary.
You will see
Serial Monitor states that the run is not a stopping-safety test.
Why it matters
A simulator result cannot establish braking distance or physical sensor behaviour.

Chapter checks

These questions refer to the chapter’s examples. Use the return links to review their answers.

Why should a ToF reading carry a status or confidence value?
Return to the chapter’s knowledge check
Which choice best fits one controlled, nearby optical zone?
Return to the chapter’s knowledge check

Return to Lidar and Optical Ranging for IoT · Browse Labs

Wokwi ESP32

Get the files

diagram.json

sketch.ino

Steps

1 Step 1

2 Step 2

3 Step 3

4 Step 4

5 Step 5

6 Step 6

Chapter checks

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6