diff --git a/arduino/v5.3/prime_logging_esp32/results.txt b/arduino/v5.3/prime_logging_esp32/results.txt
index f1d8a5e..5416575 100644
--- a/arduino/v5.3/prime_logging_esp32/results.txt
+++ b/arduino/v5.3/prime_logging_esp32/results.txt
@@ -1,17 +1,21 @@
 Calculating prime numbers in Arduino C v5.4.2023
-2023/12/23
-ESP32-S3 OTG USB with 240 MHz
+2023/12/24
+ESP32 with 240 MHz
+
+Get previous results for this ESP32:
+         100    0.000390
+        1000    0.002854
+       10000    0.029392
+      100000    0.321495
+     1000000    3.828875
+    10000000    52.244022
+    25000000    155.919083
+   100000000    857.574036
+  1000000000    0.000000
+  2147483647    0.000000
+  4294967295    0.000000
+
 
-Get previous results for this ESP32-S3:
-    last        seconds   
-         100    0.000348
-        1000    0.018474
-       10000    0.028547
-      100000    0.310781
-     1000000    3.670793
-    10000000    49.427952
-    25000000    146.725739
-   100000000    800.481140
   1000000000    15763.267578   -  4h 22min 43s
   2147483647    46706.203125   - 12h 58min 26s
   4294967295    119194.734375  - 33h  6min 34s
diff --git a/arduino/v5.3/prime_logging_esp32c3_neopixel/prime_logging_esp32c3_neopixel.ino b/arduino/v5.3/prime_logging_esp32c3_neopixel/prime_logging_esp32c3_neopixel.ino
new file mode 100644
index 0000000..95ee2f8
--- /dev/null
+++ b/arduino/v5.3/prime_logging_esp32c3_neopixel/prime_logging_esp32c3_neopixel.ino
@@ -0,0 +1,271 @@
+/* Prime numbers in Arduino C v5.4 2023/12/21 for esp32-c3 */
+#include <time.h>
+#include <math.h>
+#include <Preferences.h>
+#include <Adafruit_NeoPixel.h>
+
+#define LED_PIN 8
+#define NEOPIXEL_PIN LED_PIN   
+Adafruit_NeoPixel pixels(1, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
+
+double start;
+int column = 10;
+int found = 4;   // we already know 2, 3, 5, 7
+int divisors = found;
+int primes[6550] = {3, 5, 7};
+int RED[3] =   {64, 0, 0};
+int GREEN[3] = {0, 64, 0};
+int BLUE[3] =  {0, 0, 64};
+
+int is_prime(int number) {
+  int prime = 1;
+  for (int divider = 3; divider < (int)(sqrt(number)) + 1; divider += 2)
+  {
+    if (number % divider == 0)
+    {
+      prime = 0;
+      break;
+    }
+  }
+  return prime;
+}
+
+int find_primes(int limit) {
+  for(int number=11; number < limit + 1; number += 2) { 
+    if( is_prime(number) == 1) {
+      primes[found - 1] = number;
+      found++;
+    }
+  }
+  primes[found - 1] = limit;
+  divisors = found - 1;
+  return 1;
+}
+
+int is_prime_fast(uint32_t number) {
+  int 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;
+      break;
+    }
+    if(primes[i] > largest_divider)
+    {
+      break;
+    }
+  }
+  // Serial.print("\n");
+  return flag_prime;
+}
+
+void elapsed_time(int seconds) {
+  int hours = (int)seconds/3600;
+  int minutes = (int)(seconds/60 - hours*60);
+  int sec = (int)(seconds - minutes*60 - hours*3600);
+  Serial.print(" ");
+  Serial.print(hours);
+  Serial.print("h ");
+  Serial.print(minutes);
+  Serial.print("min ");
+  Serial.print(sec);
+  Serial.print("s ");
+}
+
+void led(int RGB[]) {
+  pixels.setPixelColor(0, pixels.Color(RGB[0], RGB[1], RGB[2]));
+  pixels.show();
+}
+
+
+
+void setup() {
+  Serial.begin(74880);
+  pixels.begin();  // INITIALIZE NeoPixel strip object (REQUIRED)
+  led(RED);
+  for (int i = 0; i < 3; i++) {
+    Serial.print(".");
+    delay(1000);
+  }
+  led(BLUE);
+  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, 203280221};
+
+
+
+  // previous run
+  const char* pref[] = {"p100", "p1000", "p10000", "p100000", "p1000000", "p10000000", "p25000000", "p100000000", "p1000000000", "p2147483647", "p4294967295"};
+  Preferences preferences;
+  preferences.begin("prime", true);
+  Serial.print("\nGet previous results for this ESP32-C3:\n");
+  Serial.print("    last        seconds   \n");
+  for(int i = 0; i < 11; i++) {
+    int spaces = 11 - (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);
+    Serial.print("\n");
+  }
+  preferences.end();
+  delay(1000);
+  led(GREEN);
+
+
+
+  // start calculating with micros() until 100 million
+  for (int i = 0; i < 8; i++) // 8
+  {
+    int last = scope[i];
+    found = 4;   // we already know 2, 3, 5, 7
+    Serial.println("\n\nPrime v5.4 in Arduino C - 2023/12/21");
+    Serial.print("Calculating prime numbers until ");
+    Serial.println(last);
+    start = micros();      // use micros() for more precision
+    int largest_divider = (int)(sqrt(last)); 
+    if(largest_divider % 2 == 0)
+    {
+      largest_divider += 1;
+    }
+    find_primes(largest_divider);
+    Serial.print("Found ");
+    Serial.print(found);
+    Serial.print(" primes until ");
+    Serial.print(largest_divider);
+    Serial.print(" to use as divisors.\n");
+    int dot = millis();
+    int column = 0;
+    for(int number = largest_divider + 2; number < last; number += 2)
+    {
+      found += is_prime_fast(number);
+      if((millis() - dot) > 1000) {
+        Serial.print(".");
+        dot = millis();
+        column += 1;
+        if(column % 2 == 0) {
+          led(RED);
+        }
+        else
+        {
+          led(GREEN);
+        }
+        if(column > 40) {
+          column = 0;
+          elapsed_time(dot/1000);
+          Serial.print(" - ");
+          Serial.print(number);
+          Serial.print(" ");
+          Serial.print((int)(number / (last / 100)));
+          Serial.print("% \n");
+        }
+      }
+    }
+    float duration = (micros() - start)/1000000;
+    if(duration > 2) {
+      Serial.print("\n");
+    }    
+    Serial.print("Found ");
+    Serial.print(found);
+    Serial.print(" prime numbers. It should be ");
+    Serial.print(reference[i]);
+    Serial.print(".\nThis took ");
+    Serial.print(duration, 6);
+    Serial.print(" seconds.");
+    elapsed_time(duration);
+    preferences.begin("prime", false);
+    preferences.putFloat(pref[i], duration);
+    preferences.end();
+  }
+
+
+
+
+
+  // start calculating with millis() from 1 billion
+  for (int i = 8; i < 11; i++)
+  {
+    uint32_t last = scope[i];
+    found = 4;   // we already know 2, 3, 5, 7
+    Serial.println("\n\nPrime v5.0 in Arduino C - 2023/12/20");
+    Serial.print("Calculating prime numbers until ");
+    Serial.println(last);
+    start = millis();
+    int largest_divider = (int)(sqrt(last)); 
+    if(largest_divider % 2 == 0)
+    {
+      largest_divider += 1;
+    }
+    find_primes(largest_divider);
+    Serial.print("Found ");
+    Serial.print(found);
+    Serial.print(" primes until ");
+    Serial.print(largest_divider);
+    Serial.print(" to use as divisors.\n");
+    int dot = millis();
+    int column = 0;
+    for(uint32_t number = largest_divider + 2; number < last; number += 2)
+    {
+      found += is_prime_fast(number);
+      if((millis() - dot) > 1000) {
+        Serial.print(".");
+        dot = millis();
+        column += 1;
+        if(column % 2 == 0) {
+          led(RED);
+        }
+        else
+        {
+          led(GREEN);
+        }
+        if(column > 40) {
+          column = 0;
+          elapsed_time(dot/1000);
+          Serial.print(" - ");
+          Serial.print(number);
+          Serial.print(" ");
+          Serial.print((int)(number / (last / 100)));
+          Serial.print("% \n");
+        }
+      }
+    }
+    float duration = (millis() - start)/1000;
+    if(duration > 2) {
+      Serial.print("\n");
+    }    
+    Serial.print("Found ");
+    Serial.print(found);
+    Serial.print(" prime numbers. It should be ");
+    Serial.print(reference[i]);
+    Serial.print(".\nThis took ");
+    Serial.print(duration, 6);
+    Serial.print(" seconds.");
+    elapsed_time(duration);
+    preferences.begin("prime", false);
+    preferences.putFloat(pref[i], duration);
+    preferences.end();
+  }
+  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++) {
+      led(BLUE);
+      delay(30);
+      pixels.clear();
+      pixels.show();
+      delay(20);   
+    }
+  }
+  Serial.print(".\n");
+}
diff --git a/arduino/v5.3/prime_logging_esp32c3_neopixel/results.txt b/arduino/v5.3/prime_logging_esp32c3_neopixel/results.txt
new file mode 100644
index 0000000..d86392a
--- /dev/null
+++ b/arduino/v5.3/prime_logging_esp32c3_neopixel/results.txt
@@ -0,0 +1,17 @@
+Calculating prime numbers in Arduino C v5.4.2023
+2023/12/25
+ESP32-C3 OTG USB with 160 MHz
+
+Get previous results for this ESP32-C3:
+    last        seconds   
+         100    0.000528
+        1000    0.005168
+       10000    0.055167
+      100000    0.620651
+     1000000    7.621645
+    10000000    106.675552
+    25000000    318.646759
+   100000000    1751.800415
+  1000000000    33369.484375
+  2147483647    91127.843750
+  4294967295    228788.000000
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/100.txt b/circuitpython/v5.3_esp32c3_luatos/100.txt
index 99ee1ae..ecf6f5c 100644
--- a/circuitpython/v5.3_esp32c3_luatos/100.txt
+++ b/circuitpython/v5.3_esp32c3_luatos/100.txt
@@ -1,3 +1,3 @@
-vcc_gnd_yd_rp2040
-Primes to 100 took 0.00799561 seconds.
+luatos_core_esp32c3
+Primes to 100 took 0.0109863 seconds.
 Found 25 primes. Should be 25.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/1000.txt b/circuitpython/v5.3_esp32c3_luatos/1000.txt
index 9788ae1..26a5f82 100644
--- a/circuitpython/v5.3_esp32c3_luatos/1000.txt
+++ b/circuitpython/v5.3_esp32c3_luatos/1000.txt
@@ -1,3 +1,3 @@
-vcc_gnd_yd_rp2040
-Primes to 1000 took 0.0639954 seconds.
+luatos_core_esp32c3
+Primes to 1000 took 0.0579834 seconds.
 Found 168 primes. Should be 168.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/10000.txt b/circuitpython/v5.3_esp32c3_luatos/10000.txt
index 8160819..7894963 100644
--- a/circuitpython/v5.3_esp32c3_luatos/10000.txt
+++ b/circuitpython/v5.3_esp32c3_luatos/10000.txt
@@ -1,3 +1,3 @@
-vcc_gnd_yd_rp2040
-Primes to 10000 took 0.758003 seconds.
+luatos_core_esp32c3
+Primes to 10000 took 0.572998 seconds.
 Found 1229 primes. Should be 1229.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/100000.txt b/circuitpython/v5.3_esp32c3_luatos/100000.txt
index 1c7cc2a..c5f5792 100644
--- a/circuitpython/v5.3_esp32c3_luatos/100000.txt
+++ b/circuitpython/v5.3_esp32c3_luatos/100000.txt
@@ -1,3 +1,3 @@
-vcc_gnd_yd_rp2040
-Primes to 100000 took 10.167 seconds.
+luatos_core_esp32c3
+Primes to 100000 took 7.22998 seconds.
 Found 9592 primes. Should be 9592.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/1000000.txt b/circuitpython/v5.3_esp32c3_luatos/1000000.txt
index b0ef192..508f233 100644
--- a/circuitpython/v5.3_esp32c3_luatos/1000000.txt
+++ b/circuitpython/v5.3_esp32c3_luatos/1000000.txt
@@ -1,3 +1,3 @@
-vcc_gnd_yd_rp2040
-Primes to 1000000 took 156.987 seconds.
+luatos_core_esp32c3
+Primes to 1000000 took 106.811 seconds.
 Found 78498 primes. Should be 78498.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/10000000.txt b/circuitpython/v5.3_esp32c3_luatos/10000000.txt
new file mode 100644
index 0000000..00bc0cf
--- /dev/null
+++ b/circuitpython/v5.3_esp32c3_luatos/10000000.txt
@@ -0,0 +1,3 @@
+luatos_core_esp32c3
+Primes to 10000000 took 1975.6 seconds.
+Found 664579 primes. Should be 664579.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/100000000.txt b/circuitpython/v5.3_esp32c3_luatos/100000000.txt
new file mode 100644
index 0000000..8878948
--- /dev/null
+++ b/circuitpython/v5.3_esp32c3_luatos/100000000.txt
@@ -0,0 +1,3 @@
+luatos_core_esp32c3
+Primes to 100000000 took 38587.1 seconds.
+Found 5761455 primes. Should be 5761455.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/1000000000.txt b/circuitpython/v5.3_esp32c3_luatos/1000000000.txt
new file mode 100644
index 0000000..5965cd3
--- /dev/null
+++ b/circuitpython/v5.3_esp32c3_luatos/1000000000.txt
@@ -0,0 +1,3 @@
+luatos_core_esp32c3
+Primes to 1000000000 took 826497.0 seconds.
+Found 50847534 primes. Should be 123456789.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/25000000.txt b/circuitpython/v5.3_esp32c3_luatos/25000000.txt
new file mode 100644
index 0000000..04e4f14
--- /dev/null
+++ b/circuitpython/v5.3_esp32c3_luatos/25000000.txt
@@ -0,0 +1,3 @@
+luatos_core_esp32c3
+Primes to 25000000 took 6334.8 seconds.
+Found 1565927 primes. Should be 1565927.
\ No newline at end of file
diff --git a/circuitpython/v5.3_esp32c3_luatos/code.py b/circuitpython/v5.3_esp32c3_luatos/code.py
index d62edbd..b343146 100644
--- a/circuitpython/v5.3_esp32c3_luatos/code.py
+++ b/circuitpython/v5.3_esp32c3_luatos/code.py
@@ -1,4 +1,4 @@
-# prime v5.3 2023-12-14 for luatos esp32c3
+# prime v5.3 2023-12-25 for luatos esp32c3
 # cycles through limits and writes to the filesystem
 
 import math, time, digitalio, board, os
@@ -52,8 +52,7 @@ def lightshow():
         time.sleep(0.2)
 
 if __name__ == "__main__":
-    lightshow() 
-    for i in range(len(scope)):
+    for i in range(len(scope)): # len(scope)
         last = scope[i]
         found = 4              # we start from 11, know 2, 3, 5, 7
         primes = [3, 5, 7]     # exclude 2 since we only test odd numbers
@@ -99,7 +98,7 @@ def lightshow():
     print('\nWrite summary')
     try:
         with open("summary.txt", "w") as fp:
-            fp.write(f'Primes calculation in Circuitpython v5.2 2023/12/11\n')
+            fp.write(f'Primes calculation in Circuitpython v5.3 2023/12/14\n')
             fp.write(board.board_id)
             fp.write('\n last       time in seconds\n')
             for i in range(len(time_calc)):
@@ -110,3 +109,4 @@ def lightshow():
 
 while True:
     lightshow()
+    
diff --git a/circuitpython/v5.3_esp32c3_luatos/summary.txt b/circuitpython/v5.3_esp32c3_luatos/summary.txt
new file mode 100644
index 0000000..3393c6c
--- /dev/null
+++ b/circuitpython/v5.3_esp32c3_luatos/summary.txt
@@ -0,0 +1,12 @@
+Primes calculation in Circuitpython v5.3 2023/12/14
+luatos_core_esp32c3
+ last       time in seconds
+ 100   0.0109863
+ 1000   0.0579834
+ 10000   0.572998
+ 100000   7.22998
+ 1000000   106.811
+ 10000000   1975.6
+ 25000000   6334.8
+ 100000000   38587.1
+ 1000000000   826497.0