i2cdetect 不显示任何地址

Question

我使用OLED 128*64显示屏与NodeMCU ESP8266。当我试图检测屏幕地址时，串口监视器显示:输入图片描述

如果有人能告诉我是什么问题，那就太好了。如何解决?

Answer 1

嗨，Mari，请试试这个I2c测试器:它会给你设备的数量和它们的地址

#include <Wire.h>
byte errorResult;           // error code returned by I2C 
byte i2c_addr;              // I2C address being pinged
byte lowerAddress = 0x08;   // I2C lowest valid address in range
byte upperAddress = 0x77;   // I2C highest valid address in range
byte numDevices;            // how many devices were located on I2C bus
void setup() {
Wire.begin();             // I2C init
Serial.begin(115200);       // search results show up in serial monitor
}
void loop() {
if (lowerAddress < 0x10)                                // pad single digit addresses with a leading "0"
Serial.print("0");
Serial.print(lowerAddress, HEX);
Serial.print(" to 0x");
Serial.print(upperAddress, HEX);
Serial.println(".");
numDevices = 0;
for (i2c_addr = lowerAddress; i2c_addr <= upperAddress; i2c_addr++ ) 
// loop through all valid I2C addresses
{
Wire.beginTransmission(i2c_addr);                     // initiate communication at current address
errorResult = Wire.endTransmission();                 // if a device is present, it will send an ack and "0" will be returned from function
if (errorResult == 0)                                 // "0" means a device at current address has acknowledged the serial communication
{
Serial.print("I2C device found at address 0x");
if (i2c_addr < 0x10)                                // pad single digit addresses with a leading "0"
Serial.print("0");
Serial.println(i2c_addr, HEX);                      // display the address on the serial monitor when a device is found
numDevices++;
}
}
Serial.print("Scan complete.  Devices found: ");
Serial.println(numDevices);
Serial.println();
delay(10000);                                           // wait 10 seconds and scan again to detect on-the-fly bus changes
}

Answer 2

接线应为I2C连接:D2→SDA, D1 ->SCL, GND ->GND， (*) ->Vcc

(*)检查你有什么oled模型，有些工作在+5V，其他在+3.3V，这可能是问题此外，通常不需要上拉电阻(检查您的型号规格)还要检查oled的规格，有时需要一些跳线设置

Answer 3

我发现了问题:我没有在板内正确插入节点。