1.Testing my Final Project input Devices

1.1) VL53L1X Distance sensor

Specifications

• Operating voltage: 3.3V/5V
• Dimension: 20mm × 24mm
• Mounting holes size: 2.0mm
• anging distance: 40 ~ 4000mm
• Ranging accuracy: ±5%
• Ranging time (min): 20ms (short distance mode), 33ms (medium/long distance mode)
• Field of view: 27°
• Laser wavelength: 940nm
• Operating temperature: -20 ~ 80°C

Pinouts of VL53L1X distance sensor:

• VCC: 3.3V/5V power input
• GND: ground
• SDA: I2C data pin
• SCL: I2C clock pin
• SHUT: shutdown control, connects to IO pin
• INT: interrupt output, connects to IO pin

Here is our reference about VL53L1X Distance sensor

Workflow Using VL53L1X distance sensor.

1. Adding library for VL53L1X distance sensor in Arduino IDE.

This was the code i have choosed for programming.

#include <Wire.h>
#include <VL53L1X.h>

VL53L1X sensor;

void setup()
{
  while (!Serial) {}
  Serial.begin(115200);
  Wire.begin();
  Wire.setClock(400000); // use 400 kHz I2C

  sensor.setTimeout(500);
  if (!sensor.init())
  {
    Serial.println("Failed to detect and initialize sensor!");
    while (1);
  }

  // Use long distance mode and allow up to 50000 us (50 ms) for a measurement.
  // You can change these settings to adjust the performance of the sensor, but
  // the minimum timing budget is 20 ms for short distance mode and 33 ms for
  // medium and long distance modes. See the VL53L1X datasheet for more
  // information on range and timing limits.
  sensor.setDistanceMode(VL53L1X::Long);
  sensor.setMeasurementTimingBudget(50000);

  // Start continuous readings at a rate of one measurement every 50 ms (the
  // inter-measurement period). This period should be at least as long as the
  // timing budget.
  sensor.startContinuous(50);
}

void loop()
{
  sensor.read();

  Serial.print("range: ");
  Serial.print(sensor.ranging_data.range_mm);
  Serial.print("\tstatus: ");
  Serial.print(VL53L1X::rangeStatusToString(sensor.ranging_data.range_status));
  Serial.print("\tpeak signal: ");
  Serial.print(sensor.ranging_data.peak_signal_count_rate_MCPS);
  Serial.print("\tambient: ");
  Serial.print(sensor.ranging_data.ambient_count_rate_MCPS);

  Serial.println();
}

1. Connections of Sensor pins with a PCB board fabricated.

I have connected the SDA pin of sensor to the SDA pin of PCB board, followed by SCL to SCL, VCC to 5V of board, and GND to GND.We have used my fabricated PCB board of week 8

Then followed by compiling and uploading my program into Arduino IDE after selecting board and port. After that clicked on “Serial Monitor”.

Our connection worked showing distances as we move the sensor.

1.2) AM321 PIR sensor.

About PIR sensor

PIR sensors are used to detect motion within the range.These sensors are small, cheap, low power and easy to use and do not wear out.They are commonly referred as “Passive Infrared” or IR motion sensors.

More details can be found from my reference link about PIR sensor.

Pinouts of AM321 PIR sensor.

• VCC(3.3V/5V) for power supply.
• GND
• OUT(Signal) as output pin.

Workflow for PIR sensor AM321 with XIAO SAMD21 board.

pin outs of my PCB board with XIAO SAMD21

Connections:

• VCC of AM321 PIR sensor to 3.3V of my PCB board
• GND of PIR sensor to GND of my PCB board.
• OUT(Signal) of PIR sensor to GPIO03 OR D3

This is the code.

#define PIR_PIN D3  // AM321 PIR sensor output connected to D3

void setup() {
    pinMode(PIR_PIN, INPUT);
    Serial.begin(115200);
}

void loop() {
    static unsigned long motionStart = 0;

    if (digitalRead(PIR_PIN) == HIGH) {
        if (motionStart == 0) {
            motionStart = millis();  // Start timing motion
        }
    } else {
        if (motionStart > 0) {
            unsigned long motionDuration = millis() - motionStart;
            motionStart = 0;  // Reset timer

            if (motionDuration < 1000) {  // Assume <50 cm movement
                Serial.println("Motion detected within 50cm!");
            }
        }
    }
    delay(100);  // Adjust sensitivity
}

Now clicked to compile and clicked upload.

I followed to clicked on serial monitor to detect the motion for my connection and it displayed the motion detected.

From the above code for PIR sensor, the PIR sensor was defined initially as ‘#define PIR _Pin D3’ where i changed pin to D3.For function ‘Void Setup() {‘, it means PIR sensor was configured as input with ‘PinMode(PIR_PIN, INPUT) and serial communication started with 115200 baud rate. Initially motion started with 0 millisecond.Motion detected within 20cm range after each motion stops with a 1 second.

Note: For more details of first trial test for above distance sensor and PIR sensor, please refer here under my week9 Input Devices assignment