Example Code for Arduino-UART Communication

Hardware Preparation

• DFRobot Beetle RP2040, 1, Purchase Link
• USB Type-C Cable, 1
• Fermion: Multifunctional Environmental Sensor (SEN0500), 1, Purchase Link

Software Preparation

• Arduino IDE: Download Link
• Raspberry Pi Pico/RP2040 SDK: Installed via Arduino Boards Manager (see Getting Started)
• DFRobot_RTU Library: Download Link
• DFRobot_EnvironmentalSensor Library: Download Link

Wiring Diagram

• BeetleRP2040: GP29(RX) (connect to) Environmental Sensor: TX(T)
• BeetleRP2040: GP28(TX) (connect to) Environmental Sensor: RX(R)
• BeetleRP2040: 3V3 (connect to) Environmental Sensor: 3V3
• BeetleRP2040: GND (connect to) Environmental Sensor: GND

Other Preparation Work

1. Open Arduino IDE.
2. Select "DFRobot Beetle RP2040" as the development board.
3. Connect the Beetle RP2040 to your computer.
4. Wire the environmental sensor to UART1 (GP28/TX1, GP29/RX1) as per the diagram.
5. Install the DFRobot_RTU and DFRobot_EnvironmentalSensor libraries via Arduino Library Manager.

Sample Code

Function: read the value of the environmental sensor and print the readings in the serial port.

#include "DFRobot_EnvironmentalSensor.h"

DFRobot_EnvironmentalSensor environment(/*addr =*/SEN050X_DEFAULT_DEVICE_ADDRESS, /*s =*/&Serial1); //define the UART interface connected to the sensor

void setup()
{
  environment.begin();  //initialize the sensor
  Serial1.begin(9600); //define the baud rate of the UART interface connected to the sensor
  Serial.begin(9600); //define the baud rate of the USB-to-serial interface
}

void loop()
{
  Serial.println("-------------------------------");
  Serial.print("Temp: ");
  Serial.print(environment.getTemperature(TEMP_C));
  Serial.println(" ℃");
  Serial.print("Temp: ");
  Serial.print(environment.getTemperature(TEMP_F));
  Serial.println(" ℉");
  Serial.print("Humidity: ");
  Serial.print(environment.getHumidity());
  Serial.println(" %");
  Serial.print("Ultraviolet intensity: ");
  Serial.print(environment.getUltravioletIntensity());
  Serial.println(" mw/cm2");
  Serial.print("LuminousIntensity: ");
  Serial.print(environment.getLuminousIntensity());
  Serial.println(" lx");
  Serial.print("Atmospheric pressure: ");
  Serial.print(environment.getAtmospherePressure(HPA));
  Serial.println(" hpa");
  Serial.print("Altitude: ");
  Serial.print(environment.getElevation());
  Serial.println(" m");
  Serial.println("-------------------------------");
  delay(500);
}

Result

Open the ArduinoIDE serial monitor, and the monitor window prints the sensor data correctly.

Additional Information

• UART1 uses pins GP28 (TX1) and GP29 (RX1) for communication.
• The environmental sensor communicates at 9600 baud (default setting).