How to Use Seeed Studio XIAO nRF54L15 Sense: Examples, Pinouts, and Specs

The Seeed Studio XIAO nRF54L15 Sense is a compact and powerful microcontroller board built around the Nordic Semiconductor nRF54L15 System-on-Chip (SoC). Designed for low-power wireless applications, this board is ideal for IoT projects, wearable devices, and environmental monitoring. It features built-in sensors for temperature, humidity, and other environmental parameters, along with Bluetooth Low Energy (BLE) support for seamless wireless connectivity.

• IoT devices and smart home systems
• Wearable technology
• Environmental monitoring and data logging
• BLE-based wireless communication
• Prototyping low-power embedded systems

Below are the key technical details of the Seeed Studio XIAO nRF54L15 Sense:

The XIAO nRF54L15 Sense features a total of 14 pins, including power, GPIO, and communication pins. Below is the pinout description:

1. Powering the Board: Connect the 3.3V and GND pins to a suitable power source. The board can also be powered via USB-C.
2. Connecting Sensors: Use the built-in sensors for environmental monitoring. For external sensors, connect them to the I2C or GPIO pins.
3. Programming: The board can be programmed using the Arduino IDE or Nordic's nRF Connect SDK. Install the necessary board support package (BSP) for the XIAO nRF54L15 Sense.
4. Wireless Communication: Use the BLE functionality to communicate with other BLE-enabled devices.

• Ensure the input voltage does not exceed 5V to avoid damaging the board.
• Use appropriate pull-up resistors for I2C communication if required.
• When using BLE, ensure the antenna area is not obstructed for optimal signal strength.
• For battery-powered applications, monitor power consumption and optimize sleep modes.

Below is an example of how to read the built-in temperature sensor and send the data over BLE:

#include <Wire.h>
#include <BLEPeripheral.h>

// Initialize BLE peripheral
BLEPeripheral blePeripheral;
BLEService tempService("1809"); // Temperature Service UUID
BLECharacteristic tempCharacteristic("2A1C", BLERead | BLENotify, 4);

// I2C address for the temperature sensor
const int tempSensorAddress = 0x48;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  while (!Serial);

  // Initialize BLE
  blePeripheral.setLocalName("XIAO nRF54L15");
  blePeripheral.setAdvertisedServiceUuid(tempService.uuid());
  blePeripheral.addAttribute(tempService);
  blePeripheral.addAttribute(tempCharacteristic);
  blePeripheral.begin();

  // Initialize I2C
  Wire.begin();
  Serial.println("BLE Temperature Sensor Ready");
}

void loop() {
  // BLE poll
  blePeripheral.poll();

  // Read temperature from the sensor
  Wire.beginTransmission(tempSensorAddress);
  Wire.write(0x00); // Command to read temperature
  Wire.endTransmission();
  Wire.requestFrom(tempSensorAddress, 2);

  if (Wire.available() == 2) {
    int tempRaw = (Wire.read() << 8) | Wire.read();
    float temperature = tempRaw * 0.02 - 273.15; // Convert to Celsius

    // Print temperature to Serial
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");

    // Update BLE characteristic
    tempCharacteristic.setValue((int)(temperature * 100)); // Send as integer
  }

  delay(1000); // Wait 1 second
}

1. Board Not Detected in Arduino IDE:

   • Ensure the correct board support package (BSP) is installed.
   • Check the USB connection and ensure the correct COM port is selected.

2. BLE Connection Fails:

   • Verify that the BLE device is within range.
   • Ensure no other devices are interfering with the BLE signal.

3. Sensors Not Responding:

   • Check the I2C connections and ensure the correct sensor address is used.
   • Verify that the sensors are enabled in the firmware.

4. High Power Consumption:

   • Use low-power modes and optimize sleep settings in your code.
   • Disable unused peripherals to reduce power draw.

Q: Can I use this board with a LiPo battery?
A: Yes, the XIAO nRF54L15 Sense supports LiPo batteries. Ensure the battery voltage is within the supported range.

Q: What is the maximum BLE range?
A: The BLE range depends on environmental factors but typically extends up to 50 meters in open space.

Q: Is the board compatible with CircuitPython?
A: Currently, the board is not officially supported by CircuitPython, but you can use the Arduino IDE or nRF Connect SDK for programming.

Q: How do I update the firmware?
A: Firmware updates can be performed using the Nordic nRF Connect tools or the Arduino IDE with the appropriate bootloader.