Table of contents
1. Introduction
The Micro SD card module TF card reader has an onboard level conversion circuit, that is, the interface level can be 5V or 3.3V, and supports Micro SD cards (≤2G) and Micro SDHC high-speed cards (≤32G). The power supply is 4.5V~5.5V, and the onboard 3.3V voltage regulator circuit supplies power for the level conversion chip and Micro SD card. The communication interface is a standard SPI interface. Through the file system and the SPI interface driver, the single-chip microcomputer system can complete the reading and writing of files in the MicroSD card. With 4 M2 screw positioning holes for easy installation.
Control interface: a total of 6 pins (GND, VCC, MISO, MOSI, SCK, CS), GND is the ground, VCC is the power supply, MISO, MOSI, SCK is the SPI bus, CS is the chip select signal pin;
2. Preparation before use
| Micro SD card module TF card reader | 1 |
|---|---|
| Original genuine Arduino uno r3 development board | 1 |
| USB2.0 printer data cable high-speed square port connection adapter cable A male to B male | 1 |
| dupont line | Slightly |
3. Test method
Use the USB2.0 printer data cable high-speed square port connection adapter cable to connect with the Arduino uno r3 development board. Connect the Arduino uno r3 development board to the Micro SD card module, and insert a Micro SD card, as shown in the figure below
| Arduino UNO | SD card module |
|---|---|
| 5V | VCC |
| GND | GND |
| 4 | MOSI |
| 11 | MOSI |
| 12 | MISO |
| 13 | SCK |
Open ArduinoIDE, first click [File], then click [SD], and finally click [CardInfo], as shown in the figure below. The 
code is as follows:
/*
SD card test
This example shows how use the utility libraries on which the'
SD library is based in order to get info about your SD card.
Very useful for testing a card when you're not sure whether its working or not.
The circuit:
SD card attached to SPI bus as follows:
** MOSI - pin 11 on Arduino Uno/Duemilanove/Diecimila
** MISO - pin 12 on Arduino Uno/Duemilanove/Diecimila
** CLK - pin 13 on Arduino Uno/Duemilanove/Diecimila
** CS - depends on your SD card shield or module.
Pin 4 used here for consistency with other Arduino examples
created 28 Mar 2011
by Limor Fried
modified 9 Apr 2012
by Tom Igoe
*/
// include the SD library:
#include <SPI.h>
#include <SD.h>
// set up variables using the SD utility library functions:
Sd2Card card;
SdVolume volume;
SdFile root;
// change this to match your SD shield or module;
// Arduino Ethernet shield: pin 4
// Adafruit SD shields and modules: pin 10
// Sparkfun SD shield: pin 8
// MKRZero SD: SDCARD_SS_PIN
const int chipSelect = 4;
void setup() {
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
Serial.print("\nInitializing SD card...");
// we'll use the initialization code from the utility libraries
// since we're just testing if the card is working!
if (!card.init(SPI_HALF_SPEED, chipSelect)) {
Serial.println("initialization failed. Things to check:");
Serial.println("* is a card inserted?");
Serial.println("* is your wiring correct?");
Serial.println("* did you change the chipSelect pin to match your shield or module?");
while (1);
} else {
Serial.println("Wiring is correct and a card is present.");
}
// print the type of card
Serial.println();
Serial.print("Card type: ");
switch (card.type()) {
case SD_CARD_TYPE_SD1:
Serial.println("SD1");
break;
case SD_CARD_TYPE_SD2:
Serial.println("SD2");
break;
case SD_CARD_TYPE_SDHC:
Serial.println("SDHC");
break;
default:
Serial.println("Unknown");
}
// Now we will try to open the 'volume'/'partition' - it should be FAT16 or FAT32
if (!volume.init(card)) {
Serial.println("Could not find FAT16/FAT32 partition.\nMake sure you've formatted the card");
while (1);
}
Serial.print("Clusters: ");
Serial.println(volume.clusterCount());
Serial.print("Blocks x Cluster: ");
Serial.println(volume.blocksPerCluster());
Serial.print("Total Blocks: ");
Serial.println(volume.blocksPerCluster() * volume.clusterCount());
Serial.println();
// print the type and size of the first FAT-type volume
uint32_t volumesize;
Serial.print("Volume type is: FAT");
Serial.println(volume.fatType(), DEC);
volumesize = volume.blocksPerCluster(); // clusters are collections of blocks
volumesize *= volume.clusterCount(); // we'll have a lot of clusters
volumesize /= 2; // SD card blocks are always 512 bytes (2 blocks are 1KB)
Serial.print("Volume size (Kb): ");
Serial.println(volumesize);
Serial.print("Volume size (Mb): ");
volumesize /= 1024;
Serial.println(volumesize);
Serial.print("Volume size (Gb): ");
Serial.println((float)volumesize / 1024.0);
Serial.println("\nFiles found on the card (name, date and size in bytes): ");
root.openRoot(volume);
// list all files in the card with date and size
root.ls(LS_R | LS_DATE | LS_SIZE);
}
void loop(void) {
}
4. Experimental phenomenon
Open the serial port assistant to get some basic information of the card
