Battery monitor example for the Banggood version of TTGO LoRa32

TTGO_LORA32_BATT_OLED.ino

const uint8_t blue = 2;
const uint8_t vbatPin = 35;
#include <Wire.h>  // Only needed for Arduino 1.6.5 and earlier
#include "SSD1306.h" // alias for `#include "SSD1306Wire.h"`
float VBAT;  // battery voltage from ESP32 ADC read
SSD1306  display(0x3c, 4, 15);
void setup() 
{
  Serial.begin(115200);
  pinMode(blue, OUTPUT);
  pinMode(vbatPin, INPUT);

  pinMode (16, OUTPUT);
  
  digitalWrite (16, LOW); // set GPIO16 low to reset OLED
  delay (50);
  digitalWrite (16, HIGH); // while OLED is running, GPIO16 must go high
  
  display.init();

  display.flipScreenVertically();
  display.setFont(ArialMT_Plain_10);
}
char string[25];
void drawFontFaceDemo(float Vbat) {
    // Font Demo1
    // create more fonts at http://oleddisplay.squix.ch/
    display.setTextAlignment(TEXT_ALIGN_LEFT);
    display.setFont(ArialMT_Plain_10);
    display.drawString(0, 0, "Battery");
    display.setFont(ArialMT_Plain_16);
    display.drawString(0, 10, "Monitoring");
    display.setFont(ArialMT_Plain_24);
    itoa(Vbat,string,10);
    sprintf(string,"%7.5f",Vbat);
    display.drawString(0, 26, string);
}

void loop() 
{
  digitalWrite(blue, 1);
  delay(100);
  digitalWrite(blue, 0);
  delay(100);
  digitalWrite(blue, 1);
  delay(100);
  
  // Battery Voltage
  VBAT = (float)(analogRead(vbatPin)) / 4095*2*3.3*1.1;
  /*
  The ADC value is a 12-bit number, so the maximum value is 4095 (counting from 0).
  To convert the ADC integer value to a real voltage you’ll need to divide it by the maximum value of 4095,
  then double it (note above that Adafruit halves the voltage), then multiply that by the reference voltage of the ESP32 which 
  is 3.3V and then vinally, multiply that again by the ADC Reference Voltage of 1100mV.
  */
  Serial.println("Vbat = "); Serial.print(VBAT); Serial.println(" Volts");
  display.clear();
  drawFontFaceDemo(VBAT);
   display.display();
  digitalWrite(blue, 0);
  delay(700);

}

Well working and documented LoRa examples and reference here: https://github.com/YogoGit/TTGO-LORA32-V1.0

Ist this possible with TTGO LoRa32 V1.0 the one from bang good without OLED?

Can't get it working...

Is soldering needed?

Comment any line that says "display"-and then something and it should work? Then again - you wouldn't see the result :-P
The code here isn't too complicated. Read it line by line and see what you'll need to make it work without a screen?

I comment out any line. But in Serial Monitor VBAT shows 0.0. :(
Maybe my TTGO Lora32 V1.0 doesnt have a internal divider or battery pin?

Oh shit... After reading line by line...
Maybe I've forgotten pinMode INPUT 😆
Need to check this tomorrow...

Could be, but I'd guess Gihub Gist isn't the place to discuss stuff like this? It's primarily a way to share tiny snippets ;-)