// The "esp_wifi_get_protocol()" call expects a 'uint8_t pointer', but actually appears to use it as a 'uint16_t pointer'...
// thereby corrupting the next variable in the program.
// https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/network/esp_wifi.html#_CPPv421esp_wifi_get_protocol16wifi_interface_tP7uint8_t


#include <WiFi.h>
#include <WiFiManager.h>

void setup() {
  Serial.begin(115200); delay(3000);
  Serial.printf("\nIDE SDK=v%s\n",ESP_ARDUINO_VERSION_STR);
  WiFi.mode(WIFI_STA); // WiFi.mode(WIFI_AP); // WIFI_IF_AP
  uint8_t x[20];
  memset(x,8,20);
  for (int y=0;y<20;y++) Serial.printf("%i ",x[y]); Serial.println(); 
  uint8_t *phy_mode=x+10;
  boolean success=(esp_wifi_get_protocol(WIFI_IF_STA,phy_mode)==ESP_OK);
  // esp_err_t esp_wifi_get_protocol(wifi_interface_t ifx, uint8_t *protocol_bitmap)
  Serial.printf("esp_wifi_get_protocol: success=%i, phy_mode=%u\n",success,*phy_mode); 
  for (int y=0;y<20;y++) Serial.printf("%i ",x[y]); Serial.println(); 
  Serial.println("Note that 2 bytes have been changed/corrupted by the call: the 'phy_mode' byte and the 'subsequent' byte"); 
}

void loop() {}