Created
August 10, 2019 14:03
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Battery monitor example for the Banggood version of TTGO LoRa32
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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); | |
} |
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 ;-)
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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?