STEM教育 · 3D打印室内温度计：基于Arduino和OLED屏幕

天冷了，养热带花草和宠物的同学们需要多留意室内温度。下面给大家推荐一个实用性强、制作简单的温度计。使用 DS18B20 温度传感器和 OLED 模块构建，这里使用的开发板是 Piksey Pico，代码是兼容 Arduino 的，你也可以使用 Arduino 来完成它。

材料清单

Arduino 或 Piksey Pico × 1
DS18B20 温度传感器 × 1
0.96 英寸 OLED 模块 × 1
电平转换器模块 × 1

编程和测试

1、将代码文件上传至 Arduino。
3D 打印的室内温度计，基于 Arduino 和 OLED 屏幕图3

2、显示器上的图形可以根据自己的具体情况来修改。
3D 打印的室内温度计，基于 Arduino 和 OLED 屏幕图4

3、将所有的组件安装到面包板上。接线方式如图所示。

代码如下：

[mw_shl_code=applescript,true]#include <U8g2lib.h>
#include <OneWire.h>
#include <DallasTemperature.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

/*
  U8glib Example Overview:
Frame Buffer Examples: clearBuffer/sendBuffer. Fast, but may not work with all Arduino boards because of RAM consumption
Page Buffer Examples: firstPage/nextPage. Less RAM usage, should work with all Arduino boards.
U8x8 Text Only Example: No RAM usage, direct communication with display controller. No graphics, 8x8 Text only.

  This is a page buffer example.
*/

// Please UNCOMMENT one of the contructor lines below
// U8g2 Contructor List (Picture Loop Page Buffer)
// The complete list is available here: https://github.com/olikraus/u8g2/wiki/u8g2setupcpp
// Please update the pin numbers according to your setup. Use U8X8_PIN_NONE if the reset pin is not connected

U8G2_SSD1306_128X64_NONAME_1_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE); // All Boards without Reset of the Display

// End of constructor list

#define SUN 0
#define SUN_CLOUD  1
#define CLOUD 2
#define RAIN 3
#define THUNDER 4

char i=0;
/********************************************************************/
// Data wire is plugged into pin 2 on the Arduino
#define ONE_WIRE_BUS 2
/********************************************************************/
// Setup a oneWire instance to communicate with any OneWire devices
// (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);
/********************************************************************/
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
/********************************************************************/

void drawWeatherSymbol(u8g2_uint_t x, u8g2_uint_t y, uint8_t symbol)
{
  // fonts used:
  // u8g2_font_open_iconic_embedded_6x_t
  // u8g2_font_open_iconic_weather_6x_t
  // encoding values, see: https://github.com/olikraus/u8g2/wiki/fntgrpiconic

  switch(symbol)
  {
case SUN:
   u8g2.setFont(u8g2_font_open_iconic_weather_6x_t);
   u8g2.drawGlyph(x, y, 69);
   break;
case SUN_CLOUD:
   u8g2.setFont(u8g2_font_open_iconic_weather_6x_t);
   u8g2.drawGlyph(x, y, 65);
   break;
case CLOUD:
   u8g2.setFont(u8g2_font_open_iconic_weather_6x_t);
   u8g2.drawGlyph(x, y, 64);
   break;
case RAIN:
   u8g2.setFont(u8g2_font_open_iconic_weather_6x_t);
   u8g2.drawGlyph(x, y, 67);
   break;
case THUNDER:
   u8g2.setFont(u8g2_font_open_iconic_embedded_6x_t);
   u8g2.drawGlyph(x, y, 67);
   break;
  }
}

void drawWeather(uint8_t symbol, int degree)
{
  drawWeatherSymbol(0, 55, symbol);
  u8g2.setFont(u8g2_font_logisoso32_tf);
  u8g2.setCursor(48+3, 55);
  u8g2.print(degree);
  u8g2.print("°C");       // requires enableUTF8Print()
}

/*
  Draw a string with specified pixel offset.
  The offset can be negative.
  Limitation: The monochrome font with 8 pixel per glyph
*/
void drawScrollString(int16_t offset, const char *s)
{
  static char buf[36]; // should for screen with up to 256 pixel width
  size_t len;
  size_t char_offset = 0;
  u8g2_uint_t dx = 0;
  size_t visible = 0;
  len = strlen(s);
  if ( offset < 0 )
  {
char_offset = (-offset)/8;
dx = offset + char_offset*8;
if ( char_offset >= u8g2.getDisplayWidth()/8 )
   return;
visible = u8g2.getDisplayWidth()/8-char_offset+1;
strncpy(buf, s, visible);
buf[visible] = '\0';
u8g2.setFont(u8g2_font_8x13_mf);
u8g2.drawStr(char_offset*8-dx, 62, buf);
  }
  else
  {
char_offset = offset / 8;
if ( char_offset >= len )
   return; // nothing visible
dx = offset - char_offset*8;
visible = len - char_offset;
if ( visible > u8g2.getDisplayWidth()/8+1 )
   visible = u8g2.getDisplayWidth()/8+1;
strncpy(buf, s+char_offset, visible);
buf[visible] = '\0';
u8g2.setFont(u8g2_font_8x13_mf);
u8g2.drawStr(-dx, 62, buf);
  }

}

void draw(const char *s, uint8_t symbol, int degree)
{
  int16_t offset = -(int16_t)u8g2.getDisplayWidth();
  int16_t len = strlen(s);
  for(;;)
  {
u8g2.firstPage();
do {
   drawWeather(symbol, degree);
   // drawScrollString(offset, s);
} while ( u8g2.nextPage() );
delay(20);
offset+=2;
if ( offset > len*8+1 )
   break;
  }
}

void setup(void) {

  /* U8g2 Project: SSD1306 Test Board */
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);

  /* U8g2 Project: T6963 Test Board */
  //pinMode(18, OUTPUT);
  //digitalWrite(18, 1);

  /* U8g2 Project: KS0108 Test Board */
  //pinMode(16, OUTPUT);
  //digitalWrite(16, 0);

  /* U8g2 Project: LC7981 Test Board, connect RW to GND */
  //pinMode(17, OUTPUT);
  //digitalWrite(17, 0);

  /* U8g2 Project: Pax Instruments Shield: Enable Backlight */
  //pinMode(6, OUTPUT);
  //digitalWrite(6, 0);

  u8g2.begin();
  u8g2.enableUTF8Print();
  sensors.begin();
}

void loop(void) {

  sensors.requestTemperatures();

  u8g2.firstPage();
  do {
   drawWeather(SUN_CLOUD, sensors.getTempCByIndex(0));
  } while ( u8g2.nextPage() );

  delay(1000);
}[/mw_shl_code][/mw_shl_code]
3D 打印外壳