Store accelerometer data in a memory and read later

Projects Programming
1

Well, I'm collecting data from an accelerometer and storing it in FRAM memory using the FRAM.h library.

The idea seems right, but I'm not getting it right.

Basically, I have a method that runs after setup and stores the data in a memory address, and another that reads the data every 5 seconds. The problem is that in the read method, the values are coming up with a correct value and then a null value.
Maybe there's a mistake in the memory addresses I'm using.

Writing method:

unsigned long writeMicroseconds;
int current_sample = 0;
void writeVibrationInformation() {
  data.rms[0] = 0.0;
  data.rms[1] = 0.0;
  data.rms[2] = 0.0;
  for (int i = 0; i < ACC_DATA_RATE; i++) {
    writeMicroseconds = micros();

    Vibration vibration = readVibration();

    if ((current_sample >= acc_sample_factor)) {
      if (current_sample <= SAMPLES)
        fram.writeFloat(i*sizeof(float), sqrt(vibration.x * vibration.x + vibration.y * vibration.y + vibration.z * vibration.z));
        printLog(String(sqrt(vibration.x * vibration.x + vibration.y * vibration.y + vibration.z * vibration.z)), true);
      current_sample = 0;
    } else
      current_sample++;

    data.rms[0] = (data.rms[0] + (sqrt((vibration.x * vibration.x)) / ACC_DATA_RATE));
    data.rms[1] = (data.rms[1] + (sqrt((vibration.y * vibration.y)) / ACC_DATA_RATE));
    data.rms[2] = (data.rms[2] + (sqrt((vibration.z * vibration.z)) / ACC_DATA_RATE));

    while (micros() < (writeMicroseconds + sampling_period_us)) {}
  }
}

Reading Method:

unsigned long readMilliseconds;
byte address = 0;

bool energy_save = false;

float temperatureValue;
int current_package = 0;
int reset_counter = 0;
bool sendDataDelay = false;
void readAndSendFRAMData() {

  if (energy_save) {
    readMilliseconds = millis();
    sendDataDelay = true;
    energy_save = false;
  } else if (millis() > (readMilliseconds + data_sender_period)) {
    sendDataDelay = true;
  }

  if (sendDataDelay) {
    bool report = false;

    if (hasFRAM) {

      int start = TRANSMISSION_DATA_PACKAGE * current_package;
      int end = (start + TRANSMISSION_DATA_PACKAGE);

      for (int i = start; i < end; i++) {
        address = i * 4;// * sizeof(float);
        float value = 0.0;
        if (address < sizeInBytes) {
          value = fram.readFloat(address);
        }
        vibrationPackage.dataPackage[(i - start)] = value;
      }

      strncpy(vibrationPackage.key, SENSOR_KEY, sizeof(vibrationPackage.key));

      vibrationPackage.type = 'P';

      vibrationPackage.start = start;
      vibrationPackage.end = min(end, SAMPLES);

      printVibrationPackage(vibrationPackage);

      radio.powerUp();

      int a = 0;
      int countSendMaxTries = 120;
      if (start == 0)
        countSendMaxTries = 60;

      while (!report) {
        report = radio.write(&vibrationPackage, sizeof(vibrationPackage));
        delay(20);
        reset_counter++;
        if (reset_counter >= countSendMaxTries) {
          radio.powerDown();
          if (start != 0)
            resetFunc();
          else {
            a++;
            if (a >= 10)
              resetFunc();
            LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
          }
        }
      }
    }

    readMilliseconds = millis();
    sendDataDelay = false;

    if (report) {
      temperatureValue += readTemperature() / package_factor;
      current_package++;
      reset_counter = 0;
    } else {
      reset_counter++;
      if (reset_counter >= 80)
        resetFunc();
    }
  }

  radio.powerDown();
  energy_save = true;
}

Values received from the accelerometer and recorded in the fram:

9.26, 9.19, 8.89, 8.32
9.19, 8.88, 9.04, 8.97
9.21, 8.91, 8.94, 8.89
9.04, 8.97, 9.12, 9.84
8.97, 8.88, 9.19, 9.03
8.55, 8.97, 9.28, 9.11
8.84, 9.04, 8.81, 8.80
8.43, 9.05, 9.21, 8.96
9.11, 8.79, 8.79, 8.89

Data package values received from fram reading:

VibrationPackage:
Size: 31 Bytes
Type: P
Key: 0000A
Data Package: 0.00 9.26 0.00 9.19 0.00 
A: 0
B: 5


Recebido: VibrationPackage:
Size: 31 Bytes
Type: P
Key: 0000A
Data Package: 8.89 0.00 8.32 0.00 9.19 
A: 5
B: 10


Recebido: VibrationPackage:
Size: 31 Bytes
Type: P
Key: 0000A
Data Package: 0.00 8.88 0.00 9.04 0.00 
A: 10
B: 15


Recebido: VibrationPackage:
Size: 31 Bytes
Type: P
Key: 0000A
Data Package: 8.97 0.00 9.21 0.00 8.91 
A: 15
B: 20


Recebido: VibrationPackage:
Size: 31 Bytes
Type: P
Key: 0000A
Data Package: 0.00 8.94 0.00 8.89 0.00 
A: 20
B: 25

Here you can see that in the data package values between the correct values there is always a 0.00

2

what microcontroller and FRAM are you using?

3

Not enough information posted.

I suggest to write a short program to read and write data from FRAM, and test it, to make sure you understand the addressing scheme.

4

FRAM: 256 K (32 K × 8) Bit I2C (MB85RC256V)
And the Microcontroller: Atmega 328p

5

I assume you are using a UNO
looks as though you are using the String class - this is not recommended on low power low SRAM micros such as the UNO - the memory can become fragmented leading to unpredictable problems and possible system crash
use C type char arrays

also as @jremington suggests write a simple test program then once it is working worry about writing complex data structures

6

I'm actually saving float values ​​in memory, I just realized that I didn't put the vibraPackage struct in the post, but the values ​​are all floats.

7

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.