adaptation STM32F411 for 2E32 calculation

arduino/v5.3/prime_logging_stm32f411/prime_logging_stm32f411.ino

@@ -1,17 +1,17 @@
-/* Prime numbers in Arduino C v5.3 2023/12/14 for esp32-s2 */
+/* Prime numbers in Arduino C v5.4 2023/12/14 for STM32F411CEU6 */
 #include <time.h>
 #include <math.h>
-
+#include <EEPROM.h>
 
 double start;
 int column = 10;
 int found = 4;   // we already know 2, 3, 5, 7
 int divisors = found;
-int primes[3400] = {3, 5, 7};
-int led = 15; // LED_BUILDIN
+uint32_t primes[6550] = {3, 5, 7};
+int led = 13; // LED_BUILTIN
 
 
-int is_prime(int number) {
+int is_prime(uint32_t number) {
   int prime = 1;
   for (int divider = 3; divider < (int)(sqrt(number)) + 1; divider += 2)
   {
@@ -24,8 +24,8 @@ int is_prime(int number) {
   return prime;
 }
 
-int find_primes(int limit) {
-  for(int number=11; number < limit + 1; number += 2) { 
+int find_primes(uint32_t limit) {
+  for(uint32_t number=11; number < limit + 1; number += 2) { 
     if( is_prime(number) == 1) {
       primes[found - 1] = number;
       found++;
@@ -36,15 +36,11 @@ int find_primes(int limit) {
   return 1;
 }
 
-int is_prime_fast(int number) {
-  int largest_divider = (int)(sqrt(number));
+int is_prime_fast(uint32_t number) {
+  uint32_t largest_divider = (int)(sqrt(number));
   int flag_prime = 1;
-  // Serial.print(number);
-  // Serial.print(" - ");
   for(int i=0; i < divisors; i++)
   {
-    // Serial.print(primes[i]);
-    // Serial.print(" ");
     if(number % primes[i] == 0) 
     {
       flag_prime = 0;
@@ -55,7 +51,6 @@ int is_prime_fast(int number) {
       break;
     }
   }
-  // Serial.print("\n");
   return flag_prime;
 }
 
@@ -79,37 +74,35 @@ void setup() {
     Serial.print(".");
     delay(1000);
   }
-  const int scope[] = {100, 1000, 10000, 100000, 1000000, 10000000, 25000000, 100000000, 1000000000};
-  const int reference[] = {25, 168, 1229, 9592, 78498, 664579, 1565927, 5761455, 50847534};
+  const uint32_t scope[] = {100, 1000, 10000, 100000, 1000000, 10000000, 25000000, 100000000, 1000000000, 2147483647, 4294967295 };
+  const int reference[] = {25, 168, 1229, 9592, 78498, 664579, 1565927, 5761455, 50847534, 105097564, 200000000};
 
   // previous run
-  const char* pref[] = {"p100", "p1000", "p10000", "p100000", "p1000000", "p10000000", "p25000000", "p100000000", "p1000000000"};
-  // Preferences preferences;
-  // preferences.begin("prime", true);
-  Serial.print("\nGet previous results for this ESP32-S2:\n");
+  Serial.print("\nGet previous results for this STM32F411CEU6:\n");
   Serial.print("    last        seconds   \n");
-  for(int i = 0; i < 9; i++) {
-    int spaces = 11 - (int)log10(scope[i]);
+  for(int i = 0; i < 11; i++) {
+    int spaces = 12 - (int)log10(scope[i]);
     for(int j = 0; j < spaces; j++) {
       Serial.print(" ");
     }
     Serial.print(scope[i]);
     Serial.print("    ");
-    // Serial.print(preferences.getFloat(pref[i], 0), 6);
+    float last_time;
+    EEPROM.get(i * 4 + 1, last_time);
+    Serial.print(last_time, 6);
     Serial.print("\n");
   }
-  // preferences.end();
 
   // start calculating
-  for (int i = 0; i < 9; i++) // 9
+  for (int i = 0; i < 11; i++) 
   {
     int last = scope[i];
     found = 4;   // we already know 2, 3, 5, 7
-    Serial.println("\n\nPrime v5.0 in Arduino C - 2023/12/14");
+    Serial.println("\n\nPrime v5.4 in Arduino C - 2023/12/16");
     Serial.print("Calculating prime numbers until ");
     Serial.println(last);
-    start = micros();      // use micros() for more precision
-    // Serial.println(start/1000000, 6);
+//    start = millis();      
+    start = micros();        // use micros() for more precision in runtimes < 70 minutes
     int largest_divider = (int)(sqrt(last)); 
     if(largest_divider % 2 == 0)
     {
@@ -123,7 +116,7 @@ void setup() {
     Serial.print(" to use as divisors.\n");
     int dot = millis();
     int column = 0;
-    for(int number = largest_divider + 2; number < last; number += 2)
+    for(uint32_t number = largest_divider + 2; number < last; number += 2)
     {
       found += is_prime_fast(number);
       if((millis() - dot) > 1000) {
@@ -139,7 +132,7 @@ void setup() {
         }
         if(column > 40) {
           column = 0;
-          elapsed_time(dot/1000);
+          elapsed_time((millis()-start)/1000);
           Serial.print(" - ");
           Serial.print(number);
           Serial.print(" ");
@@ -148,7 +141,8 @@ void setup() {
         }
       }
     }
-    float duration = (micros() - start)/1000000;
+//    float duration = (millis() - start)/1000;
+    float duration = (micros() - start)/1000000; // use micros() for more precision in runtimes < 70 minutes
     if(duration > 2) {
       Serial.print("\n");
     }    
@@ -160,21 +154,18 @@ void setup() {
     Serial.print(duration, 6);
     Serial.print(" seconds.");
     elapsed_time(duration);
-    // preferences.begin("prime", false);
-    // preferences.putFloat(pref[i], duration);
-    // preferences.end();
+    EEPROM.put(i * 4 + 1, duration);
   }
-  // preferences.end();
   Serial.print("\n");
 }
 
 void loop() {  // program finished, just keep printing some dots
   for(int i = 0; i < 80; i++) {
     Serial.print(".");
     for(int x = 0; x < 100; x++) {
-      digitalWrite(led, HIGH);  // turn the LED on (HIGH is the voltage level)
-      delay(20);                       // wait for a second
-      digitalWrite(led, LOW);   // turn the LED off by making the voltage LOW
+      digitalWrite(led, HIGH);
+      delay(20);     
+      digitalWrite(led, LOW); 
       delay(30);   
     }
   }

arduino/v5.3/results_st,32f411.txt

@@ -0,0 +1,19 @@
+Calculating prime numbers in Arduino C v5.4.2023
+2023/12/16
+STM32F411CEU6 with 100 MHz
+
+    last       time in seconds          
+          100         0.000644       
+        1,000         0.006408         
+       10,000         0.066512
+      100,000         0.722038
+    1,000,000         8.475698
+   10,000,000       114.404968
+   25,000,000       338.672211
+  100,000,000      1851.313477  
+1,000,000,000     36123.051      or 10h 2min 3s
+2,417,483,647   
+4,294,967,295                 
+
+
+