7" touchscreen I2C address problem

[ByteYourLife]

Hello,
I bought one of the official Raspberry Pi touchscreens and connected it my Raspberry Pi 3 Model B.
I installed the latest Raspbian OS und updated the OS.

The I2C wires (SDA SCL) are connected as well the 5V and GND wires. Nothing else is connected to the I2C bus.

But if I execute the command "sudo i2cdetect -y 1" I get many different I2C address displayed which are jumping and changing.
The result from "sudo i2cdetect -y 1" looks like the picture below:



This is the output from the picture:

Code: Select all

pi@robi:~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 -- -- 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 -- -- 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c -- -- 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 -- -- 74 75 76 77
pi@robi:~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          03 04 05 06 07 08 09 0a 0b 0c 0d -- --
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 -- -- 75 76 77
pi@robi:~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a -- -- 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 -- -- 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 -- -- 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77
pi@robi:~ $

Does any one has seen the same problem and know how to fix it or what the problem is?

Any help is highly appreciated.

ByteYourLife

[6by9]

Disconnect the i2c wires. They are only needed on Pi 1 models a and B. All other models have i2c already wired up the flexi cable.

[ByteYourLife]

Thank you very much 6by9 for your fast help.
You are right now everything is working fine.
Thank you very much!

[tony359]

Disconnect the i2c wires. They are only needed on Pi 1 models a and B. All other models have i2c already wired up the flexi cable.

THANK YOU 6by9

I'm appalled that this critical information is nowhere to find in all the tutorial I found on the network on how to wire the touchscreen!!!

[davidcoton]

I'm appalled that this critical information is nowhere to find in all the tutorial I found on the network on how to wire the touchscreen!!!

Whose tutorial (link)?
If its by RPF, it can be reported and corrected.
If a third party, caveat emptor!

[6by9]

The official docs are https://www.raspberrypi.org/documentati ... /README.md
The information on the I2C wires appears to have been hidden slightly now, but it's at https://www.raspberrypi.org/documentati ... /legacy.md