Example of using the SDFileSystem library on a K64F to write files from LSM6DS33 (accel and gyro)
Dependencies: FXOS8700CQ LSM6DS3 SDFileSystem mbed
Fork of 2545_SD_Card by
main.cpp
- Committer:
- eencae
- Date:
- 2016-03-11
- Revision:
- 0:5448330e1a33
- Child:
- 1:23691b50336d
File content as of revision 0:5448330e1a33:
/* 2545_SD_Card Example Example of writing data to SD card. Based on FTF2014_lab4 Example https://developer.mbed.org/teams/Freescale/wiki/FTF2014_workshop Craig A. Evans, University of Leeds, Mar 2016 */ #include "mbed.h" #include "SDFileSystem.h" // Connections to SD card holder on K64F (SPI interface) SDFileSystem sd(PTE3, PTE1, PTE2, PTE4, "sd"); // MOSI, MISO, SCK, CS Serial serial(USBTX, USBRX); // for PC debug void delete_file(char filename[]); int main() { serial.baud(115200); // full-speed! serial.printf("#### SD Card Example #####\n"); FILE *fp; // this is our file pointer wait(1); // Various examples below - can comment out ones you don't need /////////////////////// Deleting file example //////////////////////// // comment this line out if you don't want to delete the file! delete_file("/sd/test.txt"); ////////////////////// Simple writing example ////////////////////////// // open file for writing ('w') - creates file if it doesn't exist and overwrites // if it does. If you wish to add a score onto a list, then you can // append instead 'a'. This will open the file if it exists and start // writing at the end. It will create the file if it doesn't exist. fp = fopen("/sd/topscore.txt", "w"); int top_score = 56; // random example if (fp == NULL) { // if it can't open the file then print error message serial.printf("Error! Unable to open file!\n"); } else { // opened file so can write serial.printf("Writing to file...."); fprintf(fp, "%d",top_score); // ensure data type matches serial.printf("Done.\n"); fclose(fp); // ensure you close the file after writing } ////////////////////// Simple reading example ////////////////////////// // now open file for reading fp = fopen("/sd/topscore.txt", "r"); int stored_top_score = -1; // -1 to demonstrate it has changed after reading if (fp == NULL) { // if it can't open the file then print error message serial.printf("Error! Unable to open file!\n"); } else { // opened file so can write fscanf(fp, "%d",&stored_top_score); // ensure data type matches - note address operator (&) serial.printf("Read %d from file.\n",stored_top_score); fclose(fp); // ensure you close the file after reading } ///////////////////// Writing list to file example ////////////////////// // for this example, I'll create some numbers to write to file in a big list // a data logger for example will usually append to a file - at a reading // at the end rather than creating a new file fp = fopen("/sd/test.txt", "a"); if (fp == NULL) { // if it can't open the file then print error message serial.printf("Error! Unable to open file!\n"); } else { // opened file so can write serial.printf("Writing to file...."); for(int i = 1; i <= 50; i++) { float dummy = 1000.0F/i; // dummy variable fprintf(fp, "%d,%f\n",i,dummy); // print formatted string to file (CSV) } serial.printf("Done.\n"); fclose(fp); // ensure you close the file after writing } // you can comment out the writing example to check that the writing has // worked - when you run it after commenting, it should still open the // file that exists on the SD card - assuming you didn't delete it! /////////////////////// Reading from file example //////////////////////// // now open file for reading...note the 'r' fp = fopen("/sd/test.txt", "r"); if (fp == NULL) { // if it can't open the file then print error message serial.printf("Error! Unable to open file!\n"); } else { serial.printf("Reading file....\n"); int i; // create suitable variables to store the data in the file float value; // in this example, we keep reading (using fscanf) until we reach // the 'end of file'. Note we use the address operator & to write // to the variables. Also the format of the string must match what // is in the file while (fscanf(fp, "%d,%f", &i, &value) != EOF) { serial.printf("%d,%f\n",i,value); } serial.printf("Done.\n"); fclose(fp); // ensure you close the file after reading } ///////////////// Advanced Reading from file example /////////////////// // the previous example just read the values into variables and printed to // serial, we'll now read files into an array. // now open file for reading...note the 'r' fp = fopen("/sd/test.txt", "r"); int n=0; // going to store the number of lines in the file int *index_array; // pointers to create dynamic arrays later float *value_array; // note memory will be in heap rather than on the stack if (fp == NULL) { // if it can't open the file then print error message serial.printf("Error! Unable to open file!\n"); } else { serial.printf("Counting lines in file....\n"); //Since we may not know the // number of lines in the files ahead of time, we'll first count them // * means scan but don't save while (fscanf(fp, "%*d,%*f") != EOF) { n++; // increment counter when read a line } serial.printf("Read %d lines\n",n); serial.printf("Creating dynamic arrays...\n"); // calloc creates an array and initilises to 0 // malloc returns unitialised array - diffrent syntax index_array = (int *)calloc(n, sizeof (int)); value_array = (float *)calloc(n, sizeof (float)); int i=0; rewind(fp); // 'scrolled' to end of file, so go back to beginning serial.printf("Reading into arrays...\n"); while (fscanf(fp, "%d,%f",&index_array[i],&value_array[i]) != EOF) { i++; // read data into array and increment index } serial.printf("Done.\n"); fclose(fp); // ensure you close the file after reading } // we should now have the data in the arrays, will print to serial to check for(int i=0; i<n ; i++) { serial.printf("[%d] %d,%f\n",i,index_array[i],value_array[i]); } /////////////////////////////////////////////////// serial.printf("End of SD card example\n"); } void delete_file(char filename[]) { serial.printf("Deleting file '%s'...",filename); FILE *fp = fopen(filename, "r"); // try and open file if (fp != NULL) { // if it does open... fclose(fp); // close it remove(filename); // and then delete serial.printf("Done!\n"); } // if we can't open it, it doesn't exist and so we can't delete it }