I'm new to Arduino, and I can't figure out how to reduce the memory usage of my sketch. I am trying to make a heart rate and spo2 monitor with an oled screen and just compiled the codes I found online (I used the ones from the SparkFun, but I cannot test it as the code can't be uploaded to my Arduino Uno). I have looked into the link below and other forums but I can't really figure it out. Sorry if the information is already available somewhere. Here's my code:
#include <Adafruit_GFX.h> //OLED libraries
#include <Adafruit_SSD1306.h>
#include <Wire.h>
#include "MAX30105.h" //MAX3010x library
#include "heartRate.h" //Heart rate calculating algorithm
#include "spo2_algorithm.h"
MAX30105 particleSensor;
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET); //Declaring the display name (display)
#define MAX_BRIGHTNESS 255
#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__)
//Arduino Uno doesn't have enough SRAM to store 100 samples of IR led data and red led data in 32-bit format
//To solve this problem, 16-bit MSB of the sampled data will be truncated. Samples become 16-bit data.
uint16_t irBuffer[100]; //infrared LED sensor data
uint16_t redBuffer[100]; //red LED sensor data
#else
uint32_t irBuffer[100]; //infrared LED sensor data
uint32_t redBuffer[100]; //red LED sensor data
#endif
int32_t bufferLength; //data length
int32_t spo2; //SPO2 value
int8_t validSPO2; //indicator to show if the SPO2 calculation is valid
int32_t heartRate; //heart rate value
int8_t validHeartRate; //indicator to show if the heart rate calculation is valid
byte pulseLED = 11; //Must be on PWM pin
byte readLED = 13; //Blinks with each data read
void setup()
{
Serial.begin(115200); // initialize serial communication at 115200 bits per second:
pinMode(pulseLED, OUTPUT);
pinMode(readLED, OUTPUT);
// Initialize sensor
if (!particleSensor.begin(Wire, I2C_SPEED_FAST)) //Use default I2C port, 400kHz speed
{
Serial.println(F("MAX30105 was not found. Please check wiring/power."));
while (1);
}
byte ledBrightness = 60; //Options: 0=Off to 255=50mA
byte sampleAverage = 4; //Options: 1, 2, 4, 8, 16, 32
byte ledMode = 2; //Options: 1 = Red only, 2 = Red + IR, 3 = Red + IR + Green
byte sampleRate = 100; //Options: 50, 100, 200, 400, 800, 1000, 1600, 3200
int pulseWidth = 411; //Options: 69, 118, 215, 411
int adcRange = 4096; //Options: 2048, 4096, 8192, 16384
particleSensor.setup(ledBrightness, sampleAverage, ledMode, sampleRate, pulseWidth, adcRange); //Configure sensor with these settings
}
void loop() {
long irValue = particleSensor.getIR(); //Reading the IR value it will permit us to know if there's a finger on the sensor or not
//Also detecting a heartbeat
if(irValue > 7000){ //If a finger is detected
display.clearDisplay(); //Clear the display
display.setTextSize(1); //Near it display the average BPM you can display the BPM if you want
display.setTextColor(WHITE);
display.setCursor(50,0);
display.println(F("BPM"));
display.setCursor(100,0);
display.println(heartRate, DEC);
display.setCursor(50,20);
display.println(F("SPO2"));
display.setCursor(100,20);
display.println(spo2, DEC);
display.display();
if (checkForBeat(irValue) == true) //If a heart beat is detected
{
display.clearDisplay(); //Clear the display
display.setTextSize(1); //And still displays the average BPM
display.setTextColor(WHITE);
display.setCursor(50,0);
display.println(F("BPM"));
display.setCursor(100,0);
display.println(heartRate, DEC);
display.setCursor(50,20);
display.println(F("SPO2"));
display.setCursor(100,20);
display.println(spo2, DEC);
display.display();
tone(3,1000); //And tone the buzzer for a 100ms you can reduce it it will be better
delay(100);
noTone(3);
{
bufferLength = 100; //buffer length of 100 stores 4 seconds of samples running at 25sps
//read the first 100 samples, and determine the signal range
for (byte i = 0 ; i < bufferLength ; i++)
{
while (particleSensor.available() == false) //do we have new data?
particleSensor.check(); //Check the sensor for new data
redBuffer[i] = particleSensor.getRed();
irBuffer[i] = particleSensor.getIR();
particleSensor.nextSample(); //We're finished with this sample so move to next sample
Serial.print(F("red="));
Serial.print(redBuffer[i], DEC);
Serial.print(F(", ir="));
Serial.println(irBuffer[i], DEC);
}
}
//calculate heart rate and SpO2 after first 100 samples (first 4 seconds of samples)
maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);
//Continuously taking samples from MAX30102. Heart rate and SpO2 are calculated every 1 second
while (1)
{
//dumping the first 25 sets of samples in the memory and shift the last 75 sets of samples to the top
for (byte i = 25; i < 100; i++)
{
redBuffer[i - 25] = redBuffer[i];
irBuffer[i - 25] = irBuffer[i];
}
//take 25 sets of samples before calculating the heart rate.
for (byte i = 75; i < 100; i++)
{
while (particleSensor.available() == false) //do we have new data?
particleSensor.check(); //Check the sensor for new data
digitalWrite(readLED, !digitalRead(readLED)); //Blink onboard LED with every data read
redBuffer[i] = particleSensor.getRed();
irBuffer[i] = particleSensor.getIR();
particleSensor.nextSample(); //We're finished with this sample so move to next sample
//send samples and calculation result to terminal program through UART
Serial.print(F("red="));
Serial.print(redBuffer[i], DEC);
Serial.print(F(", ir="));
Serial.print(irBuffer[i], DEC);
Serial.print(F(", HR="));
Serial.print(heartRate, DEC);
Serial.print(F(", HRvalid="));
Serial.print(validHeartRate, DEC);
Serial.print(F(", SPO2="));
Serial.print(spo2, DEC);
Serial.print(F(", SPO2Valid="));
Serial.println(validSPO2, DEC);
}
//After gathering 25 new samples recalculate HR and SP02
maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);
}
}
}
}
Here's the error message:
Sketch uses 19836 bytes (61%) of program storage space. Maximum is 32256 bytes.
Global variables use 2097 bytes (102%) of dynamic memory, leaving -49 bytes for local variables. Maximum is 2048 bytes.
Not enough memory; see https://support.arduino.cc/hc/en-us/articles/360013825179 for tips on reducing your footprint.
data section exceeds available space in board
Compilation error: data section exceeds available space in board
I really need the help as this is for our final. Please be kind.
