Editing Wemos D1 Mini (section)

=Notes=
Most sample sketches show D2 and D1 as the SDA and SCL pins, but some show D3 and D5.  Both work.

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==DS18B20 temperature sensor==
Reference: [http://www.esp8266learning.com/wemos-mini-ds18b20-temperature-sensor-example.php Wemos mini DS18B20 temperature sensor example.]
<br>
[[File:Wemos-mini-and-ds18b20.png|480px]]<br clear=all>

 <nowiki>#include <OneWire.h>
 
// OneWire DS18S20, DS18B20, DS1822 Temperature Example
 
OneWire  ds(D4);  // on pin D4 (a 4.7K resistor is necessary)
 


// =============================== setup() ===============================
void setup(void) 
{
  Serial.begin(115200);
}
 


// =============================== loop() ===============================
void loop(void) 
{
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  byte addr[8];
  float celsius, fahrenheit;
 
  if ( !ds.search(addr)) 
  {
    ds.reset_search();
    delay(250);
    return;
  }
 
 
  if (OneWire::crc8(addr, 7) != addr[7]) 
  {
      Serial.println("CRC is not valid!");
      return;
  }
  Serial.println();
 
  // the first ROM byte indicates which chip
  switch (addr[0]) 
  {
    case 0x10:
      type_s = 1;
      break;
    case 0x28:
      type_s = 0;
      break;
    case 0x22:
      type_s = 0;
      break;
    default:
      Serial.println("Device is not a DS18x20 family device.");
      return;
  } 
 
  ds.reset();
  ds.select(addr);
  ds.write(0x44, 1);        // start conversion, with parasite power on at the end  
  delay(1000);
  present = ds.reset();
  ds.select(addr);    
  ds.write(0xBE);         // Read Scratchpad
 
  for ( i = 0; i < 9; i++) 
  {           
    data[i] = ds.read();
  }
 
  // Convert the data to actual temperature
  int16_t raw = (data[1] << 8) | data[0];
  if (type_s) {
    raw = raw << 3; // 9 bit resolution default
    if (data[7] == 0x10) 
    {
      raw = (raw & 0xFFF0) + 12 - data[6];
    }
  } 
  else 
  {
    byte cfg = (data[4] & 0x60);
    if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 93.75 ms
    else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
    else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
 
  }
  celsius = (float)raw / 16.0;
  fahrenheit = celsius * 1.8 + 32.0;
  Serial.print("  Temperature = ");
  Serial.print(celsius);
  Serial.print(" Celsius, ");
  Serial.print(fahrenheit);
  Serial.println(" Fahrenheit");
}</nowiki>

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==Make an XBM image file==
First, make your image in Photoshop.  To stay in the blue area of a 128x64 display, make the canvas no larger than 128x48.<br>
Draw the monochrome image on the canvas then save it as a png file.<br>
Next, go to [[https://www.online-utility.org/image/convert/to/XBM Online Image Converter]]<br>
When you download the XBM file, edit it.  
* Change the first two lines to change the image number to the imageName.<br>
* Change the third line to "const uint8_t imageName_bits[] PROGMEM = {"<br>
* Save the file as imageName.h<br>
<br>
To display it on the OLED display, import the imagName.h file, then in loop(), add this code:
 display.drawXbm(x, y, imageName_width, imageName_height, imageName_bits);
x,y are the top-left corner of the image.  _width, _height and _bits are defined in the .h file.

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