ESP32 cansat next

Introduction

Some interesting coding stuff

snprintf

printf, print

Each ASCII character takes 1 byte. You can store exactly 128 ASCII characters in the above char array.

char report[128];  
  memset(report, 0, sizeof(report));
  snprintf(report, sizeof(report), "%4.2f, %4.2f, %4.2f, %4.2f, %4.2f, %4.2f",
    ax, ay, az, gx, gy, gz);
  Serial.println(report);

Radio

To send strings, use sendData( str ); command.

SD Card

First, open the file const String filepath = "/filename.csv"; and then append the data and linebreak

  appendFile(filepath, data);
  appendFile(filepath, "\n");