virtualdave
Well-known member
Hi all,
Just want to make sure these numbers looked right. I'm testing read and write speeds to the EEPROM of the Teensy 3 and here are the numbers I'm seeing:
reading 100 byte array ~= 93 microseconds
writing 100 byte array ~= 118 microseconds
reading 2 bytes, doing some quick processing (adding the two bytes, incrementing, splitting the sum back into 2 bytes and writing back to EEPROM ~= 345 microseconds.
This was mainly a test to see if this action would get in the way of other processes happening on the micro (that last time test is what I am most interested in). Do these numbers seem reasonable?
The sketch I used is below.
Thanks,
David
Just want to make sure these numbers looked right. I'm testing read and write speeds to the EEPROM of the Teensy 3 and here are the numbers I'm seeing:
reading 100 byte array ~= 93 microseconds
writing 100 byte array ~= 118 microseconds
reading 2 bytes, doing some quick processing (adding the two bytes, incrementing, splitting the sum back into 2 bytes and writing back to EEPROM ~= 345 microseconds.
This was mainly a test to see if this action would get in the way of other processes happening on the micro (that last time test is what I am most interested in). Do these numbers seem reasonable?
The sketch I used is below.
Thanks,
David
Code:
// +++++++++++++++++++++ libraries +++++++++++++++++++++ //
#include <EEPROM.h>
// +++++++++++++++++++++ general variables +++++++++++++++++++++ //
int statusLED = 13;
// +++++++++++++++++++++ timers +++++++++++++++++++++ //
elapsedMicros processingTimer;
unsigned long readTime;
unsigned long writeTime;
unsigned long readWriteTime;
const int arraySize = 100;
unsigned long readWriteNumber = 0;
byte data[arraySize];
byte serialIn;
void setup()
{
Serial.begin(921600); // USB
pinMode(statusLED, OUTPUT); // declare pin as output
// flashy flashy
for (int i=0; i <= 25; i++){ // blink LED so we know its alive
digitalWrite(statusLED, HIGH);
delay(20);
digitalWrite(statusLED, LOW);
delay(20);
}
resetEEPROM();
createDataSet();
delay(1000);
}
void loop() {
// +++++++++++++++++++++ check USB for messages +++++++++++++++++++++ //
while (Serial.available() > 0) { // mail call from CPU
serialIn = Serial.read();
if (serialIn == 114) { // 'r'
resetEEPROM();
Serial.print("zeroing EEPROM");
Serial.write(10);
delay(1000);
}
} // end USB check
// +++++++++++++++++++++ EEPROM read test +++++++++++++++++++++ //
processingTimer = 0;
readEEPROM();
readTime = processingTimer;
delay(100);
// +++++++++++++++++++++ EEPROM write test +++++++++++++++++++++ //
processingTimer = 0;
writeEEPROM();
writeTime = processingTimer;
delay(100);
// +++++++++++++++++++++ EEPROM read/write test +++++++++++++++++++++ //
processingTimer = 0;
readWriteEEPROM();
readWriteTime = processingTimer;
delay(100);
// +++++++++++++++++++++ report times +++++++++++++++++++++ //
Serial.print("read time = ");
Serial.print(readTime);
Serial.write(32);
Serial.print("write time = ");
Serial.print(writeTime);
Serial.write(32);
Serial.print("read&write time = ");
Serial.print(readWriteTime);
Serial.write(32);
Serial.print("read&write number = ");
Serial.print(readWriteNumber);
/* // for debugging
Serial.write(32);
for (int i = 0; i < arraySize; i++) {
Serial.print(data[i]);
Serial.write(32);
Serial.print(EEPROM.read(i));
Serial.write(32);
}
*/
Serial.write(10);
delay(1000);
} // end main loop()
void createDataSet() {
for (int i = 0; i < arraySize; i++) {
data[i] = random(0, 256);
EEPROM.write(i, data[i]);
}
} // end createDataSet()
void readEEPROM()
{
for (int i = 0; i < arraySize; i++) {
data[i] = EEPROM.read(i);
}
} // end read EEPROM
void writeEEPROM()
{
for (int i = 0; i < arraySize; i++) {
EEPROM.write(i, data[i]);
}
} // end write EEPROM
void readWriteEEPROM()
{
readWriteNumber = (EEPROM.read(14) << 8) + EEPROM.read(15);
readWriteNumber++;
if (readWriteNumber > 65535) readWriteNumber = 0;
EEPROM.write(14, (readWriteNumber >> 8 & 255));
EEPROM.write(15, (readWriteNumber & 255));
} // end readWrite EEPROM
void resetEEPROM()
{
for (int i = 0; i < 2048; i++) {
EEPROM.write(i, 255); // note 255 = default values
}
} // end reset EEPROM
Last edited:
