I2C SCANNER NOT WORKING

Projects Networking, Protocols, and Devices
1

Problem with I2C scanner in that it loops saying it has found address at every iteration

Sample 1 to 65 in total

I2C device found at address 0x3E !
I2C device found at address 0x3F !
I2C device found at address 0x40 !
I2C device found at address 0x41 !
I2C device found at address 0x42 !
I2C device found at address 0x43 !
I2C device found at address 0x44 !
I2C device found at address 0x45 !
I2C device found at address 0x46 !
I2C device found at address 0x47 !
I2C device found at address 0x48 !
I2C device found at address 0x49 !
I2C device found at address 0x4A !
I2C device found at address 0x4B !
I2C device found at address 0x4C !
I2C device found at address 0x4D !
I2C device found at address 0x4E !
I2C device found at address 0x4F !
I2C device found at address 0x50 !

this is with 1 x I2C device (2004 lcd) and I wish to add 2 more I2C so I need the address properly.

Anyone any ideas please as I am stumped

Thanks in advance

2

Missing three things:

post your code
post a schematic of your setup
post a HIGH QUALITY picture of your build where we can see clearly, how you have wired your modules

3

Noiasca

Many thanks for your reply, Not sure yet if I am an idiot or newbie.

see files attached for the info requested, the block of text in serial monitor.txt get repeated after approx 3 seconds

Uno connections.jpg
Uno connections.jpg1920×1080 432 KB

4

Kaybee327:
Anyone any ideas please as I am stumped

Remove the wires connected to A4 and A5 on the UNO.

What happens then when you run the I2C scan ?

5

Available range of I2C address: 0x00 - 0x7F. The following sketch checks the presence of devices in this range:

#include<Wire.h>
byte busStatus;

void setup()
{
  Serial.begin(9600);
  Wire.begin();
  for (int i2cAddress = 0x00; i2cAddress < 0x80; i2cAddress++)
  {
    Wire.beginTransmission(i2cAddress);
    busStatus = Wire.endTransmission();
    if (busStatus == 0x00)
    {
      Serial.print("I2C Device found at address: 0x");
      Serial.println(i2cAddress, HEX);
    }
    else
    {
      Serial.print("I2C Device not found at address: 0x");
      Serial.println(i2cAddress, HEX);
    }
  }
}

void loop()
{

}
6

srnet:
Remove the wires connected to A4 and A5 on the UNO.

What happens then when you run the I2C scan ?

I get the following on monitor

Devices found:
No I2C devices found
Devices found:
No I2C devices found
Devices found:
No I2C devices found
Devices found:
No I2C devices found
Devices found:
No I2C devices found

So it looks as if sketch works - as this repeats at the 5 second delay

7

GolamMostafa:
Did a copy paste and nothing on serial monitor just curser flashing

8

This is what I have got on my Serial Monitor after uploading my sketch of Post#4 in Arduino UNO. Please, check your I2C Bus wiring. What Arduino are you using?
i2cScanner.png

i2cScanner.png

9

noiasca:
post your code
post a schematic of your setup
post a HIGH QUALITY picture of your build where we can see clearly, how you have wired your modules

you have provided this picture:

Uno connections.jpg
Uno connections.jpg1920×1080 432 KB

now, please tell me by the picture
The yellow wire goes to A5 or A4 and ?
The brown wire goes to A4 or A3 and ?
The brown wire goes to VIN or GND or GND and ?
The red wire goes to 5V or 3.3V and ?

in other word's ...
your picture doesn't tell much about your setup
we are still missing your sketch
we are still missing your schematic

10

sorry I thought it was clear

scl on i2c device yellow cable to A5 on Uno
sda on i2c device brown cable to A4 on Uno
gnd on i2c device to gnd on Uno
5v on i2c device to 5v on Uno

Eventually I found I had a faulty Uno. >:( >:( >:( Uno binned and now works fine :slight_smile: :slight_smile: :slight_smile:

Many thanks for replies guy's

Keith