Gravity: LTR390 UV Light Sensor (280nm-430nm, UVA, UVB) (แท้ DFRobot)

I2C Connection Diagram

UART Connection Diagram

Features

• Support I2C and UART communication
• 3.3V & 5V compatible
• 13 to 20 bits effective resolution
• Adjustable gain range: 1, 3, 6, 9 and 18
• Interrupt function, programmable upper and lower thresholds
• Close to human eye spectral response

Applications

• UV intensity detection
• Light intensity detection
• Weather experiments for teaching
• Light detection experiments
• Devices for monitoring UV index
• Devices for outdoor UV detection

Specification

• Chip: LTR390-UV-01
• Operating Voltage: DC 3.3V to 5V
• Operating Current: about 2.73mA (18-bit data acquisition with a time of 100ms)
• Communication Interface: I2C, UART
• UV Response Wavelength: 280nm to 430nm
• ALS Spectral Response Wavelength: 450nm to 700nm
• Output Type: digital output
• Dimension: 32mm×27mm/1.26×1.06”

Documents

• Product wiki
• STP 3D Model
• 2D CAD Dimension
• 2D_CAD
• Schematics
• UV Datasheet

Shipping List

• Gravity: LTR390-UV Sensor × 1
• Gravity-4P I2C/UART Sensor Cable × 1

Tutorial for Arduino UNO

7.1 Hardware Requirements

• DFRduino UNO R3 (or similar) x 1
• Gravity: LTR390-UV Sensor

7.2 Software Requirements

• Arduino IDE
• Download and install the DFRobot_LTR390UV Library (About how to install the library?)

7.3 Connection Diagram

I2C Connection Diagram

Pin Connections:

UV Sensor: + (to) Arduino UNO: 5V

UV Sensor: - (to) Arduino UNO: GND

UV Sensor: D (to) Arduino UNO: SDA

UV Sensor: C (to) Arduino UNO: SCL

UART Connection Diagram

Pin Connections:

UV Sensor: + (to) Arduino UNO: 5V

UV Sensor: - (to) Arduino UNO: GND

UV Sensor: T (to) Arduino UNO: 4

UV Sensor: R (to) Arduino UNO: 5

7.4 Sample Code

I2C Mode

Ambient Light

#include "DFRobot_LTR390UV.h"
DFRobot_LTR390UV ltr390(/*addr = */LTR390UV_DEVICE_ADDR, /*pWire = */&Wire);

void setup()
{
Serial.begin(115200);
while(ltr390.begin() != 0){
Serial.println(" Sensor initialize failed!!");
delay(1000);
}
Serial.println(" Sensor initialize success!!");
ltr390.setALSOrUVSMeasRate(ltr390.e18bit,ltr390.e100ms);//18-bit data, sampling time of 100ms
ltr390.setALSOrUVSGain(ltr390.eGain3);//Gain of 3
ltr390.setMode(ltr390.eALSMode);//Set ambient light mode
}
void loop()
{
float als = 0;
als = ltr390.readALSTransformData();//Get data converted from ambient light intensity, which can only be used in ambient light mode
Serial.print("ALS:");
Serial.print(als);
Serial.println("Lux");
delay(1000);
}

Result

Serial print ambient light data (in an office with strong light).

Note: Ambient Light Reference Range

UV Light

#include "DFRobot_LTR390UV.h"
DFRobot_LTR390UV ltr390(/*addr = */LTR390UV_DEVICE_ADDR, /*pWire = */&Wire);

void setup()
{
Serial.begin(115200);
while(ltr390.begin() != 0){
Serial.println(" Sensor initialize failed!!");
delay(1000);
}
Serial.println(" Sensor initialize success!!");
ltr390.setALSOrUVSMeasRate(ltr390.e18bit,ltr390.e100ms);//18-bit data, sampling time of 100ms
ltr390.setALSOrUVSGain(ltr390.eGain3);//Gain of 3
ltr390.setMode(ltr390.eUVSMode);//Set UV mode
}
void loop()
{
uint32_t data = 0;
data = ltr390.readOriginalData();//Get UV raw data
Serial.print("data:");
Serial.println(data);
delay(1000);
}

Result

Serial print UV raw data (in the environment without direct sunlight on sunny day).

UART Mode

Ambient Light

#include "DFRobot_LTR390UV.h"
#include <SoftwareSerial.h>
#define UARTMODE //UART mode

SoftwareSerial mySerial(/*rx =*/4, /*tx =*/5);
DFRobot_LTR390UV ltr390(/*addr =*/LTR390UV_DEVICE_ADDR, /*s =*/&mySerial);

void setup()
{
#define UARTMODE
mySerial.begin(9600);
Serial.begin(115200);
while(ltr390.begin() != 0){
Serial.println(" Sensor initialize failed!!");
delay(1000);
}
Serial.println(" Sensor initialize success!!");
ltr390.setALSOrUVSMeasRate(ltr390.e18bit,ltr390.e100ms);//18-bit data, sampling time of 100ms
ltr390.setALSOrUVSGain(ltr390.eGain3);//Gain of 3
ltr390.setMode(ltr390.eALSMode);//Set ambient light mode
}

void loop()
{
float als = 0;
als = ltr390.readALSTransformData();//Get the data converted from ambient light intensity, which can only be used in ambient light mode
Serial.print("ALS:");
Serial.print(als);
Serial.println("Lux");
delay(100);
}

Result

Serial print ambient light data (in an office with strong light).

UV Light

#include "DFRobot_LTR390UV.h"
#include <SoftwareSerial.h>
#define UARTMODE //UART mode

SoftwareSerial mySerial(/*rx =*/4, /*tx =*/5);
DFRobot_LTR390UV ltr390(/*addr =*/LTR390UV_DEVICE_ADDR, /*s =*/&mySerial);

void setup()
{
#define UARTMODE
mySerial.begin(9600);
Serial.begin(115200);
while(ltr390.begin() != 0){
Serial.println(" Sensor initialize failed!!");
delay(1000);
}
Serial.println(" Sensor initialize success!!");
ltr390.setALSOrUVSMeasRate(ltr390.e18bit,ltr390.e100ms);//18-bit data, sampling time of 100ms
ltr390.setALSOrUVSGain(ltr390.eGain3);//Gain of 3
ltr390.setMode(ltr390.eUVSMode);//Set UV mode
}

void loop()
{
uint32_t data = 0;
data = ltr390.readOriginalData();//Get UV raw data
Serial.print("data:");
Serial.println(data);
delay(100);
}

Result

Serial print UV raw data (in the environment without direct sunlight on sunny day).

8. API

 /**
* @fn begin
* @brief Init SEN0540 device
* @return Return value init status
* @retval 0 Succeed
* @retval -1 Failed
*/
int8_t begin(void);

/**
* @fn setMode
* @brief Set data collecting mode for module
* @param mode select data collecting mode
* @return NONE
*/
void setMode(eModel_t mode);

/**
* @fn setALSOrUVSMeasRate
* @brief Set data bit and sampling time of module, the sampling time must be greater than the time the bit needs
* @n --------------------------------------------------------------------------------------------------------
* @n | bit7 | bit6 | bit5 | bit4 | bit3 | bit2 | bit1 | bit0 |
* @n ---------------------------------------------------------------------------------------------------------
* @n | Reserved | ALS/UVS Resolution | Reserved | ALS/UVS Measurement Rate |
* @n ---------------------------------------------------------------------------------------------------------
* @n | ALS/UVS Resolution |000|20 Bit, Conversion time = 400ms |
* @n | |001|19 Bit, Conversion time = 200ms |
* @n | |010|18 Bit, Conversion time = 100ms(default) |
* @n | |011|17 Bit, Conversion time = 50ms |
* @n | |100|16 Bit, Conversion time = 25ms |
* @n | |110/111|Reserved |
* @n ---------------------------------------------------------------------------------------------------------
* @n | ALS/UVS Measurement Rate |000|25ms |
* @n | |001|50ms |
* @n | |010|100ms (default) |
* @n | |011|200ms |
* @n | |100|500ms |
* @n | |101|1000ms |
* @n | |110/111|2000ms |
* @n ---------------------------------------------------------------------------------------------------------
* @param bit Set data bit
* @param time Set sampling time
* @return None
*/
void setALSOrUVSMeasRate(eResolution bit,eMeasurementRate time);

/**
* @fn setALSOrUVSGain
* @brief Set sensor gain
* @n ---------------------------------------------------------------------------------------------------------
* @n | bit7 | bit6 | bit5 | bit4 | bit3 | bit2 | bit1 | bit0 |
* @n ---------------------------------------------------------------------------------------------------------
* @n | Reserved | ALS/UVS Gain Range |
* @n ---------------------------------------------------------------------------------------------------------
* @n | ALS/UVS Gain Range |000|Gain Range: 1 |
* @n | |001|Gain Range: 3 (default) |
* @n | |010|Gain Range: 6 |
* @n | |011|Gain Range: 9 |
* @n | |100|Gain Range: 18 |
* @n | |110/111|Reserved |
* @n ---------------------------------------------------------------------------------------------------------
* @param data Control data
* @return None
*/
void setALSOrUVSGain(eGainRange data);


/**
* @fn readData
* @brief Get raw data
* @return Return the obtained raw data
*/
uint32_t readOriginalData(void);