better analogRead

hardware/esp8266com/esp8266/cores/esp8266/core_esp8266_wiring_analog.c

@@ -21,34 +21,13 @@
 #include "wiring_private.h"
 #include "pins_arduino.h"
 
+extern uint16_t readvdd33(void);
+
 void analogReference(uint8_t mode) {}
 
 extern int __analogRead(uint8_t pin) {
   if(pin == 17){
-    //return system_adc_read();
-    uint8_t i;
-    uint16_t data[8];
-
-    rom_i2c_writeReg_Mask(0x6C,2,0,5,5,1);
-
-    ESP8266_REG(0xD5C) |= (1 << 21);
-    while ((ESP8266_REG(0xD50) & (7 << 24)) > 0);
-    ESP8266_REG(0xD50) &= ~(1 << 1);
-    ESP8266_REG(0xD50) |= (1 << 1);
-    delayMicroseconds(2);
-    while ((ESP8266_REG(0xD50) & (7 << 24)) > 0);
-
-    read_sar_dout(data);
-    rom_i2c_writeReg_Mask(0x6C,2,0,5,5,1);
-
-    while ((ESP8266_REG(0xD50) & (7 << 24)) > 0);
-    ESP8266_REG(0xD5C) &= ~(1 << 21);
-    ESP8266_REG(0xD60) |= (1 << 0);
-    ESP8266_REG(0xD60) &= ~(1 << 0);
-
-    uint16_t tout = 0;
-    for (i = 0; i < 8; i++) tout += data[i];
-    return tout >> 4;//tout is 10 bits fraction
+    return readvdd33() >> 2; // readvdd33 is 12 bit
   }
   return digitalRead(pin) * 1023;
 }