ESP32 Arduino驱动0.91“ OLED

0.91“ OLED实物

I2C引脚定义

采用I2C通信，必然涉及到引脚的定义，将I2C使用到的ESP32的引脚在程序中体现出来。采用Wire.h中的setPins() 或者begin()函数均可设置ESP32的具体引脚用于I2C通信。

    //call setPins() first, so that begin() can be called without arguments from libraries
    bool setPins(int sda, int scl);
    
    bool begin(int sda=-1, int scl=-1, uint32_t frequency=0); // returns true, if successful init of i2c bus
      // calling will attemp to recover hung bus

setPins() 和begin()函数的具体实现在Wire.cpp中可见：

bool TwoWire::setPins(int sdaPin, int sclPin)
{
    if(i2c) {
        log_e("can not set pins if begin was already called");
        return false;
    }
    sda = sdaPin;
    scl = sclPin;
    return true;
}

bool TwoWire::begin(int sdaPin, int sclPin, uint32_t frequency)
{
    if(sdaPin < 0) { // default param passed
        if(num == 0) {
            if(sda==-1) {
                sdaPin = SDA;    //use Default Pin
            } else {
                sdaPin = sda;    // reuse prior pin
            }
        } else {
            if(sda==-1) {
                log_e("no Default SDA Pin for Second Peripheral");
                return false; //no Default pin for Second Peripheral
            } else {
                sdaPin = sda;    // reuse prior pin
            }
        }
    }

    if(sclPin < 0) { // default param passed
        if(num == 0) {
            if(scl == -1) {
                sclPin = SCL;    // use Default pin
            } else {
                sclPin = scl;    // reuse prior pin
            }
        } else {
            if(scl == -1) {
                log_e("no Default SCL Pin for Second Peripheral");
                return false; //no Default pin for Second Peripheral
            } else {
                sclPin = scl;    // reuse prior pin
            }
        }
    }

    sda = sdaPin;
    scl = sclPin;
    i2c = i2cInit(num, sdaPin, sclPin, frequency);
    if(!i2c) {
        return false;
    }

    flush();
    return true;

}

Arduino程序

//  Author: Nick
//  Date:22 Sep,2021

//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2.1 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

//ESP32 Arduino驱动0.91" OLED
//NODEMCU-32 V1.2
//Arduino V1.8.16
//参考链接：
//未说明SDA和SCL引脚设定：http://www.taichi-maker.com/homepage/reference-index/display-reference-index/arduino-oled-application/
//SDA和SCL在ware.begin()中定义：https://blog.csdn.net/qq_42805977/article/details/107765966

#include 

// 引入驱动OLED0.91所需的库
#include 
#include 

#define SCREEN_WIDTH 128 // 设置OLED宽度,单位:像素
#define SCREEN_HEIGHT 32 // 设置OLED高度,单位:像素

// 自定义重置引脚,虽然教程未使用,但却是Adafruit_SSD1306库文件所必需的
#define OLED_RESET 4
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup()
{
  Wire.begin(/*SDA*/17,/*SCL*/16);
  // 初始化OLED并设置其IIC地址为 0x3C
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
}

void loop()
{
  words_display();
  display.display();
}

void words_display()
{
  // 清除屏幕
  display.clearDisplay();

  // 设置字体颜色,白色可见
  display.setTextColor(WHITE);

  //设置字体大小
  display.setTextSize(1.5);

  //设置光标位置
  display.setCursor(0, 0);
  display.print("0.91 OLED");

  display.setCursor(0, 10);
  display.print("Run time: ");
  //打印自开发板重置以来的秒数：
  display.print(millis() / 1000);
  display.print(" s");

  display.setCursor(0, 20);
  display.print("Author: ");
  display.print("Nick");
}

参考链接

1）说明整体实现思路及库添加注意事项，未说明SDA和SCL引脚设定：http://www.taichi-maker.com/homepage/reference-index/display-reference-index/arduino-oled-application/

2）说明SDA和SCL引脚设定，即SDA和SCL在Wire.begin()中定义：https://blog.csdn.net/qq_42805977/article/details/107765966

void setup() 
{
  Wire.begin(/*SDA*/12,/*SCL*/14);
}