struct data_size

struct_data_size.ino

typedef struct {
  uint32_t _salt;
  uint16_t volt;
  int16_t data1;
  int16_t data2;
  uint8_t devid;
} data;

data sensor_data;

void setup() {
  Serial.begin(115200);
  Serial.println("");
  Serial.println(sizeof(sensor_data));
}

void loop() {

}

!
typedef struct {
uint32_t _salt;
uint16_t volt;
int16_t data1;
} data;

--> pro mini : 8
--> esp : 8

typedef struct {
uint32_t _salt;
uint16_t volt;
int16_t data1;
uint8_t devid;
} data;

--> pro mini : 9
--> esp : 12

typedef struct {
uint32_t _salt;
uint16_t volt;
int16_t data1;
int16_t data2;
} data;

--> pro mini : 10
--> esp : 12

typedef struct {
uint32_t _salt;
uint16_t volt;
int16_t data1;
int16_t data2;
uint8_t devid;
} data;

--> pro mini : 11
--> esp : 12

me-no-dev:
AVR is 8 bit
ESP is 32bit
on the esp it goes in 4 byte steps.