jwd83
commented
6 years ago Here is a very basic implementation via the mySD library.
#include <mySD.h>
#define MICROSD_PIN_CHIP_SELECT 4
#define MICROSD_PIN_MOSI 13
#define MICROSD_PIN_MISO 19
#define MICROSD_PIN_SCK 5
File root;
void setup()
{
Serial.begin(115200);
Serial.print("Initializing SD card...");
/* initialize SD library with SPI pins */
if (!SD.begin(MICROSD_PIN_CHIP_SELECT, MICROSD_PIN_MOSI, MICROSD_PIN_MISO, MICROSD_PIN_SCK)) {
Serial.println("initialization failed!");
return;
}
Serial.println("initialization done.");
/* Begin at the root "/" */
root = SD.open("/");
if (root) {
printDirectory(root, 0);
root.close();
} else {
Serial.println("error opening test.txt");
}
/* open "test.txt" for writing */
root = SD.open("test.txt", FILE_WRITE);
/* if open succesfully -> root != NULL
then write string "Hello world!" to it
*/
if (root) {
root.println("Hello world!");
root.flush();
/* close the file */
root.close();
} else {
/* if the file open error, print an error */
Serial.println("error opening test.txt");
}
delay(1000);
/* after writing then reopen the file and read it */
root = SD.open("test.txt");
if (root) {
/* read from the file until there's nothing else in it */
while (root.available()) {
/* read the file and print to Terminal */
Serial.write(root.read());
}
root.close();
} else {
Serial.println("error opening test.txt");
}
Serial.println("done!");
}
void loop()
{
}
void printDirectory(File dir, int numTabs) {
while(true) {
File entry = dir.openNextFile();
if (! entry) {
break;
}
for (uint8_t i=0; i<numTabs; i++) {
Serial.print('\t'); // we'll have a nice indentation
}
// Print the name
Serial.print(entry.name());
/* Recurse for directories, otherwise print the file size */
if (entry.isDirectory()) {
Serial.println("/");
printDirectory(entry, numTabs+1);
} else {
/* files have sizes, directories do not */
Serial.print("\t\t");
Serial.println(entry.size());
}
entry.close();
}
}
Ldsrc2008
Grippy98
lytruns
jonashoechst
adrianomourapeixoto
Hello,
I have been scratching my head trying to get the Heltec LoRa WiFi ESP32 board to talk to a MicroSD card properly using the Arduino IDE. I am using a breakout board I have used with a 32u4 & 328p and verified those can write to the SD card. I've also tried a few other breakout boards and cards to rule those out as well as a few different heltec lora esp32 boards (I own about a half dozen of them now). I have tried both your example code (which appears to use the same chip select pin as the onboard LoRa SPI), have tried passing a different CS in SD.begin, have tried using the "mySD" library for the ESP32 where you can specify all lines (MOSI, MISO, SCK and CS) in SD.begin.... all to no avail. When I've tried scoping the MOSI, MISO, SCK & CS line it seems like the ESP32 is attempting to communicate with the MicroSD MUCH faster than it does with the onboard LoRa chip. Do you have a working example for using MicroSD with this LoRa board? I noticed that you use a few unconventional pins compared to the standard ESP32 pinout on the LoRa board. I am curious if that might be causing any potential issues. For instance to get another hardware UART working I had to modify...
Documents\Arduino\hardware\espressif\esp32\cores\esp32\HardwareSerial.cpp
...in order to get a functional second hardware serial line I needed. I really want to use this board as the centerpiece of a project I am working on but this is unfortunately quite the hangup at the moment.