[SOLVED] arduino save int variable value on SD
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Hi, how can I save an int variable value on m5stack? (like eeprom)
is it possible to save it on sd card?tnks
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I'm not sure I quite understand your question. Do you want to log the output of a variable to a text file on the SD?
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on esp8266, to save/read a value in to eeprom, I do:
#include <EEPROM.h> int address = 0; EEPROM.begin(512); byte x = sonar.convert_cm(echoTime); delay(1000); EEPROM.write(address, x); delay(1000); EEPROM.commit(); delay(1000); x = EEPROM.read(address); delay (500);how can I do to save/read x variable on sd with m5?
tnks a lot
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M5Stack has the same "EEPROM" (Which is really a simulation that simply uses a small partition in the flash memory.) If I am not mistaken the code you quote should work still on the ESP32 (and thus on the M5Stack).
ESP32's have something called NVM, which stores key-value pairs in another partition of the same flash. In the Arduino world, "Preferences.h" provides a wrapper to use these functions. Have a look here for an example that stores a value (the number of times the ESP was booted) in flash.
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How many cycle before dead of flash partition?
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I would like to save some variables, like I did with EEPROM on esp8266, but on M5Stack sd.. (to kill sd card instead of esp32 memory)
I'm trying this sketch:
// http://forum.m5stack.com/topic/184/problems-writing-to-sd-card #include <M5Stack.h> //Micro SD / TF Card Test String cal; String lum; String unit; bool brght = 0; bool ftmt = 1; int x = 1680; void listDir(fs::FS &fs, const char * dirname, uint8_t levels) { // Print blank line on screen M5.Lcd.printf(" \n "); M5.Lcd.printf(" \n "); Serial.printf("Listing directory: %s\n", dirname); M5.Lcd.printf("Listing directory: %s\n", dirname); File root = fs.open(dirname); if (!root) { Serial.println("Failed to open directory"); M5.Lcd.println("Failed to open directory"); return; } if (!root.isDirectory()) { Serial.println("Not a directory"); M5.Lcd.println("Not a directory"); return; } File file = root.openNextFile(); while (file) { if (file.isDirectory()) { Serial.print(" DIR : "); M5.Lcd.print(" DIR : "); Serial.println(file.name()); M5.Lcd.println(file.name()); if (levels) { listDir(fs, file.name(), levels - 1); } } else { Serial.print(" FILE: "); M5.Lcd.print(" FILE: "); Serial.print(file.name()); M5.Lcd.print(file.name()); Serial.print(" SIZE: "); M5.Lcd.print(" SIZE: "); Serial.println(file.size()); M5.Lcd.println(file.size()); } file = root.openNextFile(); } } void readFile(fs::FS &fs, const char * path) { Serial.printf("Reading file: %s\n", path); M5.Lcd.printf("Reading file: %s\n", path); File file = fs.open(path); if (!file) { Serial.println("Failed to open file for reading"); M5.Lcd.println("Failed to open file for reading"); return; } Serial.print("Read from file: "); M5.Lcd.print("Read from file: "); while (file.available()) { int ch = file.read(); Serial.write(ch); M5.Lcd.write(ch); } } void writeFile(fs::FS &fs, const char * path, const char * message) { Serial.printf("Writing file: %s\n", path); M5.Lcd.printf("Writing file: %s\n", path); File file = fs.open(path, FILE_WRITE); if (!file) { Serial.println("Failed to open file for writing"); M5.Lcd.println("Failed to open file for writing"); return; } if (file.print(message)) { Serial.println("File written"); M5.Lcd.println("File written"); } else { Serial.println("Write failed"); M5.Lcd.println("Write failed"); } } void setup() { M5.begin(); Wire.begin(); Serial.begin(115200); // Lcd display M5.Lcd.setBrightness(100); M5.Lcd.fillScreen(BLACK); M5.Lcd.setCursor(0, 10); M5.Lcd.setTextColor(WHITE); M5.Lcd.setTextSize(2); // Page Header M5.Lcd.fillScreen(BLACK); M5.Lcd.setCursor(0, 05); M5.Lcd.printf("Testing SD Card Functions:\r\n"); ///////////////////////////////////////////////////////////////////////// cal = String("cal = ") + String(x) + "\r\n"; lum = String("lum = ") + String(brght) + "\r\n"; unit = String("unit = ") + String(ftmt) + "\r\n"; writeFile(SD, "/cal.txt", cal.c_str()); // questa funziona!!!! writeFile(SD, "/lum.txt", lum.c_str()); // questa funziona!!!! writeFile(SD, "/unit.txt", unit.c_str()); // questa funziona!!!! ///////////////////////////////////////////////////////////////////////// M5.Lcd.printf(""); // Print blank line on screen M5.Lcd.printf(" \n "); // Print blank line on screen M5.Lcd.printf(" \n "); readFile(SD, "/cal.txt"); readFile(SD, "/lum.txt"); readFile(SD, "/unit.txt"); } void loop() { // put your main code here, to run repeatedly: M5.update(); }but I can't understand how to read from sd and use the variables in the sketch..
I need to read and write two boolean state and one int variables ..
I'm a newbi and all the sketch I found on line that use sd.h library doesn't work on M5Stackif I upload read/write arduino sd example, this is the serial monitor output:
error opening test.txt
please help
thanks a lot
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@yellowelise said in arduino save int variable value:
How many cycle before dead of flash partition?
I'm interested too
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@cepics
Have you tried playing with the sd read and write examples? -
@ajb2k3 said in arduino save int variable value:
@cepics
Have you tried playing with the sd read and write examples?yes this one
/* SD card read/write This example shows how to read and write data to and from an SD card file The circuit: * SD card attached to SPI bus as follows: ** MOSI - pin 11 ** MISO - pin 12 ** CLK - pin 13 ** CS - pin 4 (for MKRZero SD: SDCARD_SS_PIN) created Nov 2010 by David A. Mellis modified 9 Apr 2012 by Tom Igoe This example code is in the public domain. */ #include <SPI.h> #include <SD.h> File myFile; 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("Initializing SD card..."); if (!SD.begin(4)) { Serial.println("initialization failed!"); while (1); } Serial.println("initialization done."); // open the file. note that only one file can be open at a time, // so you have to close this one before opening another. myFile = SD.open("test.txt", FILE_WRITE); // if the file opened okay, write to it: if (myFile) { Serial.print("Writing to test.txt..."); myFile.println("testing 1, 2, 3."); // close the file: myFile.close(); Serial.println("done."); } else { // if the file didn't open, print an error: Serial.println("error opening test.txt"); } // re-open the file for reading: myFile = SD.open("test.txt"); if (myFile) { Serial.println("test.txt:"); // read from the file until there's nothing else in it: while (myFile.available()) { Serial.write(myFile.read()); } // close the file: myFile.close(); } else { // if the file didn't open, print an error: Serial.println("error opening test.txt"); } } void loop() { // nothing happens after setup }it compile but the serial monitor say:
error opening test.txtright now, with an example from here, I can write an int variable in a file on sd
#include <M5Stack.h> int cal = 2000; void setup() { M5.begin(); Wire.begin(); Serial.begin(115200); File file = SD.open("/cal.txt", FILE_WRITE); if (!file) { Serial.println("Failed to open file for writing"); return; } if (file.print(cal)) { Serial.println("File written"); } else { Serial.println("Write failed"); } } void loop() { // put your main code here, to run repeatedly: }and I can read the file with
#include <M5Stack.h> int ch; void setup() { M5.begin(); Wire.begin(); Serial.begin(115200); File file = SD.open("/cal.txt"); if (!file) { Serial.println("Failed to open file for reading"); return; } Serial.print("Read from file: "); M5.Lcd.print("Read from file: "); while (file.available()) { ch = file.read(); Serial.write(ch); M5.Lcd.write(ch); } } void loop() { // put your main code here, to run repeatedly: }but I can't use the "ch" variable ..
if I add, on the "read" sketch
int y = ch + 2000; Serial.print(y);in the serial monitor I have:
M5Stack initializing...O������� Read from file: 2000 20482048 instead of 4000
now I'm searching how to convert ASCII to binary
thanks for interest..
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Hello,if you want use eeprom, suggest try this example in arduino ide:
file->Examples->Preferences -
