Hi,
I'm new here and to Arduinos & coding, so please excuse my lack of knowledge as I'm still learning.
I have created a datalogger logging accelerator and temp & humidity data. I'm looking to log data at around 50Hz, which I can get no problem if I'm not writing to the SD card and just writing to the serial monitor. As soon as I ask it to write to the SD card I can only get around 25Hz.
I've put my code together using various tutorials and although it may not be the most efficient it works, except the write speed.
Can anyone suggest anything to help increase the write speed to 50Hz or beyond if possible??
Thank you
I'm using:-
Nano
Adafruit SD Module
Adafruit LIS3DH Accelerometer
DHT22 Temp & Humidity Sensor
DS2321 RTC
Here is the code I'm using, as I've said I haven't been doing this for long (about 1 month or so) so please excuse any glaring errors, inefficiencies and housekeeping.
I have removed all the print.serial to try and help speed things up but I don't think it's helped too much.
Thank you
#include <SD.h> //SD Card Module
#include <DS3231.h> //RTC
#include <Adafruit_LIS3DH.h> //Accelerometer
#include <dht.h> //Temp Sensor
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
//Temp Sensor
#define dataPin 4 // Defines pin number to which the sensor is connected
dht DHT;
//SD Card Module
File sdcard_file;
int CS_pin = 10; // Pin 10 on Arduino Uno
//RTC
DS3231 rtc(SDA, SCL);
//Accelerometer Module
Adafruit_LIS3DH lis = Adafruit_LIS3DH();
//Millis() function
#define Accelerometer_Intival 20 //Accelerometer reading intival in milliseconds
#define Tempertaure_Intival 60000 //Temperature reading intival in milliseconds
unsigned long currentMillis;
unsigned long Acc_Time;
unsigned long Temp_Time;
void setup() {
Serial.begin(115200);
Acc_Time = millis(); //initial start time
Temp_Time = millis(); //initial start time
rtc.begin(); //Start RCT
lis.begin(); //Start Accelerometer
lis.setRange(LIS3DH_RANGE_4_G); // 2, 4, 8 or 16 G!
//Temp Sensor Setup
int readData = DHT.read22(dataPin); // DHT22/AM2302
float temp = DHT.temperature; // Gets the values of the temperature
float humid = DHT.humidity; // Gets the values of the humidity
// SD Card Initialization - called once on initial power up
if (SD.begin())
sdcard_file = SD.open("data1.txt", FILE_WRITE);
if (sdcard_file) {
sdcard_file.println("### NEW EVENT ###"); //Denotes new event
sdcard_file.close(); // close the file
}
}
void loop() {
currentMillis = millis();
accel();
temp();
}
void accel() //Read accelerometer and write to SD card
{
if(currentMillis > Acc_Time + Accelerometer_Intival)
{
//Accelerometer Read (normalised m/s^2)
sensors_event_t event;
lis.getEvent(&event);
//Write to SD Card
sdcard_file = SD.open("data1.txt", FILE_WRITE);
if (sdcard_file) {
sdcard_file.print(rtc.getDateStr());
sdcard_file.print("\t");
sdcard_file.print(rtc.getTimeStr());
sdcard_file.print("\t");
sdcard_file.print(event.acceleration.x);
sdcard_file.print("\t");
sdcard_file.print(event.acceleration.y);
sdcard_file.print("\t");
sdcard_file.println(event.acceleration.z);
sdcard_file.close(); // close the file
Acc_Time = currentMillis;
}
}
}
void temp() //Read Teamp and Humidity and wirte to SD card
{
if(currentMillis > Temp_Time + Tempertaure_Intival)
{
//Temp Read
int readData = DHT.read22(dataPin); // DHT22/AM2302
float temp = DHT.temperature; // Gets the values of the temperature
float humid = DHT.humidity; // Gets the values of the humidity
//Write to SD Card
sdcard_file = SD.open("data1.txt", FILE_WRITE);
if (sdcard_file) {
sdcard_file.print(rtc.getDateStr());
sdcard_file.print("\t");
sdcard_file.print(rtc.getTimeStr());
sdcard_file.print("\t");
sdcard_file.print("\t");
sdcard_file.print("\t");
sdcard_file.print("\t");
sdcard_file.print((float)humid, 2);
sdcard_file.print("\t");
sdcard_file.println((float)temp, 2);
sdcard_file.close(); // close the file
}
Temp_Time = currentMillis;
}
}
The reason for the several tabs in the temp & humidity is so they're in separate columns in the csv when I copy the data from the SD card.
Thanks again
