diff --git a/cores/esp32/Print.cpp b/cores/esp32/Print.cpp
index 3636d99e658..e5d388ec588 100644
--- a/cores/esp32/Print.cpp
+++ b/cores/esp32/Print.cpp
@@ -58,7 +58,7 @@ size_t Print::printf(const char *format, ...)
         va_end(arg);
         return 0;
     };
-    if(len >= sizeof(loc_buf)){
+    if(len >= (int)sizeof(loc_buf)){  // comparation of same sign type for the compiler
         temp = (char*) malloc(len+1);
         if(temp == NULL) {
             va_end(arg);
diff --git a/cores/esp32/WMath.cpp b/cores/esp32/WMath.cpp
index 931ac96637b..078e18a8767 100644
--- a/cores/esp32/WMath.cpp
+++ b/cores/esp32/WMath.cpp
@@ -36,25 +36,17 @@ void randomSeed(unsigned long seed)
     }
 }
 
-long random(long howbig)
+long random( long howsmall, long howbig );
+long random( long howbig )
 {
-    uint32_t x = esp_random();
-    uint64_t m = uint64_t(x) * uint64_t(howbig);
-    uint32_t l = uint32_t(m);
-    if (l < howbig) {
-        uint32_t t = -howbig;
-        if (t >= howbig) {
-            t -= howbig;
-            if (t >= howbig)
-                t %= howbig;
-        }
-        while (l < t) {
-            x = esp_random();
-            m = uint64_t(x) * uint64_t(howbig);
-            l = uint32_t(m);
-        }
-    }
-    return m >> 32;
+  if ( howbig == 0 )
+  {
+    return 0 ;
+  }
+  if (howbig < 0) {
+    return (random(0, -howbig));
+  }
+  return esp_random() % howbig;
 }
 
 long random(long howsmall, long howbig)
diff --git a/cores/esp32/esp32-hal-rmt.c b/cores/esp32/esp32-hal-rmt.c
index a220119d316..309cd13b327 100644
--- a/cores/esp32/esp32-hal-rmt.c
+++ b/cores/esp32/esp32-hal-rmt.c
@@ -88,9 +88,9 @@ struct rmt_obj_s
 {
     bool allocated;
     EventGroupHandle_t events;
-    int channel;
-    int buffers;
-    int data_size;
+    uint32_t channel;
+    uint32_t buffers;
+    uint32_t data_size;
     uint32_t* data_ptr;
     rmt_rx_data_cb_t cb;
     void * arg;
@@ -133,7 +133,7 @@ static xSemaphoreHandle g_rmt_block_lock = NULL;
 
 static rmt_obj_t* _rmtAllocate(int pin, int from, int size)
 {
-    size_t i;
+    int i;
     // setup how many buffers shall we use
     g_rmt_objects[from].buffers = size;
 
@@ -539,10 +539,10 @@ float rmtSetTick(rmt_obj_t* rmt, float tick)
 
 rmt_obj_t* rmtInit(int pin, bool tx_not_rx, rmt_reserve_memsize_t memsize)
 {
-    int buffers = memsize;
+    uint32_t buffers = memsize;
     rmt_obj_t* rmt = NULL;
-    size_t i = 0;
-    size_t j = 0;
+    uint32_t i = 0;
+    uint32_t j = 0;
 
     // create common block mutex for protecting allocs from multiple threads
     if (!g_rmt_block_lock) {
diff --git a/cores/esp32/esp32-hal-spi.c b/cores/esp32/esp32-hal-spi.c
index 39ad027be55..16ff3b65d10 100644
--- a/cores/esp32/esp32-hal-spi.c
+++ b/cores/esp32/esp32-hal-spi.c
@@ -1003,7 +1003,7 @@ static void __spiTransferBytes(spi_t * spi, const uint8_t * data, uint8_t * out,
     if(!spi) {
         return;
     }
-    int i;
+    uint32_t i;
 
     if(bytes > 64) {
         bytes = 64;
@@ -1298,7 +1298,7 @@ void spiWriteNL(spi_t * spi, const void * data_in, uint32_t len){
 #if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32
     spi->dev->miso_dlen.usr_miso_dbitlen = 0;
 #endif
-        for (int i=0; i<c_longs; i++) {
+        for (size_t i=0; i<c_longs; i++) {
             spi->dev->data_buf[i] = data[i];
         }
 #if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3
@@ -1333,11 +1333,11 @@ void spiTransferBytesNL(spi_t * spi, const void * data_in, uint8_t * data_out, u
         spi->dev->mosi_dlen.usr_mosi_dbitlen = (c_len*8)-1;
         spi->dev->miso_dlen.usr_miso_dbitlen = (c_len*8)-1;
         if(data){
-            for (int i=0; i<c_longs; i++) {
+            for (size_t i=0; i<c_longs; i++) {
                 spi->dev->data_buf[i] = data[i];
             }
         } else {
-            for (int i=0; i<c_longs; i++) {
+            for (size_t i=0; i<c_longs; i++) {
                 spi->dev->data_buf[i] = 0xFFFFFFFF;
             }
         }
@@ -1349,17 +1349,17 @@ void spiTransferBytesNL(spi_t * spi, const void * data_in, uint8_t * data_out, u
         while(spi->dev->cmd.usr);
         if(result){
             if(c_len & 3){
-                for (int i=0; i<(c_longs-1); i++) {
+                for (size_t i=0; i<(c_longs-1); i++) {
                     result[i] = spi->dev->data_buf[i];
                 }
                 uint32_t last_data = spi->dev->data_buf[c_longs-1];
                 uint8_t * last_out8 = (uint8_t *)&result[c_longs-1];
                 uint8_t * last_data8 = (uint8_t *)&last_data;
-                for (int i=0; i<(c_len & 3); i++) {
+                for (size_t i=0; i<(c_len & 3); i++) {
                     last_out8[i] = last_data8[i];
                 }
             } else {
-                for (int i=0; i<c_longs; i++) {
+                for (size_t i=0; i<c_longs; i++) {
                     result[i] = spi->dev->data_buf[i];
                 }
             }
@@ -1439,7 +1439,7 @@ void ARDUINO_ISR_ATTR spiWritePixelsNL(spi_t * spi, const void * data_in, uint32
 #if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32
     spi->dev->miso_dlen.usr_miso_dbitlen = 0;
 #endif
-        for (int i=0; i<c_longs; i++) {
+        for (size_t i=0; i<c_longs; i++) {
             if(msb){
                 if(l_bytes && i == (c_longs - 1)){
                     if(l_bytes == 2){
diff --git a/cores/esp32/esp32-hal-timer.c b/cores/esp32/esp32-hal-timer.c
index e0cfda10222..b6552b89377 100644
--- a/cores/esp32/esp32-hal-timer.c
+++ b/cores/esp32/esp32-hal-timer.c
@@ -47,7 +47,7 @@ static hw_timer_t timer_dev[4] = {
 // timer_init() will list thru all timers and return free timer handle)
 
 
-uint64_t inline timerRead(hw_timer_t *timer){
+inline uint64_t timerRead(hw_timer_t *timer){
 
     uint64_t value;
     timer_get_counter_value(timer->group, timer->num,&value);
diff --git a/cores/esp32/esp32-hal-uart.c b/cores/esp32/esp32-hal-uart.c
index 0dbe9e52d76..785b2bdbd6e 100644
--- a/cores/esp32/esp32-hal-uart.c
+++ b/cores/esp32/esp32-hal-uart.c
@@ -535,7 +535,7 @@ int log_printfv(const char *format, va_list arg)
 {
     static char loc_buf[64];
     char * temp = loc_buf;
-    int len;
+    uint32_t len;
     va_list copy;
     va_copy(copy, arg);
     len = vsnprintf(NULL, 0, format, copy);
diff --git a/cores/esp32/stdlib_noniso.c b/cores/esp32/stdlib_noniso.c
index d30febd97f8..e1e9eed6d41 100644
--- a/cores/esp32/stdlib_noniso.c
+++ b/cores/esp32/stdlib_noniso.c
@@ -163,7 +163,7 @@ char * dtostrf(double number, signed int width, unsigned int prec, char *s) {
     // Round correctly so that print(1.999, 2) prints as "2.00"
     // I optimized out most of the divisions
     double rounding = 2.0;
-    for (uint32_t i = 0; i < prec; ++i)
+    for (unsigned int  i = 0; i < prec; ++i)
         rounding *= 10.0;
     rounding = 1.0 / rounding;
 
@@ -171,7 +171,7 @@ char * dtostrf(double number, signed int width, unsigned int prec, char *s) {
 
     // Figure out how big our number really is
     double tenpow = 1.0;
-    int digitcount = 1;
+    unsigned int digitcount = 1;
     while (number >= 10.0 * tenpow) {
         tenpow *= 10.0;
         digitcount++;