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");

Simple code

A simple code to read data and send that via radio and store to SD card.

Declare

First declare the variables:

#include <TinyGPS++.h>
#include "CanSatNeXT.h"

#define GPS_BAUDRATE 9600  // The default baudrate of NEO-6M is 9600
TinyGPSPlus gps;  // the TinyGPS++ object
const String filepath = "/filename.csv";

long tradio = 0;
long treset = 0; //Time from reset
float ax;
float ay;
float az;
float t;
float p; 
float lat = 0;
float lng = 0;
float alt = 0;
float speed = 0;
float so2;  // Connect to pin 33

Initialize

Start the serial monitor, and software serial. Find the GPS module and start CanSatInitialization. Note that the radio needs a number in parenthesis.

void setup() {
  Serial.begin(9600);
  Serial2.begin(GPS_BAUDRATE, SERIAL_8N1, 16, 17);

  Serial.println(F("ESP32 - GPS module"));
  Serial.println(F("Lat, Lon, Alt, speed [m/s], Datetime"));

  // Start all CanSatNeXT on-board systems.
  CanSatInit();
}