Gravity: Serial Data Logger V2.0 for Arduino (แท้ DFRobot)

• Supports storage in TXT and CSV file formats.
• Significantly improves startup time and runtime stability.
• Supports scheduled creation of files for more flexible storage.
• Added USB port to make reading files more convenient.

Board Overview

Connect Diagram

•  
• With USB function, no card reader required
• Onboard 128MB Flash memory, no TF card required
• Support multiple baud rates, good compatibility
• LED indicator for viewing data writing status visually
• Supports storage in TXT and CSV file formats
• Supports scheduled creation of files for more flexible storage

• Supply Voltage: 3.3V~5V
• Operating Current: 10mA
• USB Protocol: USB2.0
• Operating Temperature Range: -20℃~65℃
• Operating Humidity Range: 5%RH~85%RH
• Dimension: 32*27mm/1.26*1.06”

•  
• Gravity: Serial Data Logger x1
• 2.54-10P Black Single-row Connector x1
• Gravity-4P I2C/UART Sensor Cable

• Product Wiki
• Schematics
• Dimensions
• step & dxf

For First Time Use

1. If the storage is not formatted, format the storage first. The file system is FAT32.
2. Power on the module for over 2 seconds (not from USB host) to make the module automatically generate the CONFIG.TXT file, and the SD light will blink once.
3. Check whether the CONFIG.TXT file is generated normally, if not, refer to FAQ please. You can change the module communication baud rate and file storage name by changing CONFIG.TXT file.
4. Connect the module to the maincontroller serial port to store data.

Configuration file parameters  Baud: Serial communication baud rate selection (00 corresponds to 2400 baud rate, 01 corresponds to 4800 baud rate). The module baud rate must match the baud rate of the main control serial port printing in order to store data normally.

FileNum: The file sequence number for the next new file (FileNum=0099, the next generated file name will be FILE0099.txt). The file sequence number automatically increments. If the file already exists, it will overwrite the current file.

FileFormat: File storage format, 0-TXT, 1-CSV.

Time: Automatically create files on schedule, 0-Do not create files on schedule, N-Create files every N minutes to store data [N: 0~10080 (one week)].

Note

1. Don't send data to the module serial port before CONFIG.TXT file is generated.
2. Don't connect the USB and serial port at the same time.
3. Connect a PC through USB. It is recommended to eject the USB flash drive before removing the module.

Features

• With USB function, no card reader required
• Onboard 128MB Flash memory, no TF card required
• Support multiple baud rates, good compatibility
• LED indicator for viewing data writing status visually
• Supports storage in TXT and CSV file formats.
• Supports scheduled creation of files for more flexible storage.

Applications

• Offline data collection
• Capture product debug logs
• Robots and drones debug

Specification

• Supply Voltage: 3.3V~5V
• Operating Current: 10mA
• USB Protocol: USB2.0
• Operating Temperature Range: -20℃~65℃
• Operating Humidity Range: 5%RH~85%RH
• Dimension: 32×27mm/1.26×1.06”

Pinout

The SD LED indicator indicates data interaction status between module and storage. It blinks when data is being written or a new file is being created.

Tutorial

Requirements

• Hardware
  • Arduino UNO R3 x 1
  • Gravity: Serial Data Logger x 1
  • M-M/F-M/F-F Jumper wires

• Software
  • Arduino IDE

Connection Diagram

Sample Code 1 - Write Data

Write data to the module through Serial.print, save a file every once in a while.

#define SPIN 6 //Connect to the module Pin S, trigger to save files at low level
uint16_t i = 0;

void setup(void)
{
Serial.begin(9600);
delay(2000); //To aviod data lost, delay a period of time to wait for the module to start
pinMode(SPIN, OUTPUT);
digitalWrite(SPIN, HIGH);
}

void loop(void)
{
Serial.println(String(i));
i++;
if((i % 10) == 0){
digitalWrite(SPIN, LOW);
delay(500);
digitalWrite(SPIN, HIGH);
}
delay(300);
}

Sample Code 2 - Write data in CSV format

NOTE: In the config.txt file, set FileFormat to 1

#define SPIN 6 //Connect to the module Pin S, trigger to save files at low level
uint16_t i = 0;

void setup(void)
{
Serial.begin(9600);
delay(2000); //To aviod data lost, delay a period of time to wait for the module to start
pinMode(SPIN, OUTPUT);
digitalWrite(SPIN, HIGH);
}

void loop(void)
{
Serial.println(String(i));
i++;
if((i % 10) == 0){
digitalWrite(SPIN, LOW);
delay(500);
digitalWrite(SPIN, HIGH);
}
delay(300);
}

FAQ