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I've been building an autonomous boat with a raspi zero, and today I added a new i2c device. I first disconnected two other I2C devices I had attached. I then used i2cdetect -y 1 to verify that no address was taken (since nothing was attached anymore). After this I connected the new device and then fired up i2cdetect -y 1 again, which shows me this:

$ 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 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 73 74 75 76 77    

I disconnected it again to verify that things were still ok, but even after disconnecting the new i2c-device I still saw the same thing. I then disconnected all jumper wires and usb connections (except for power) and did a reboot, but it still showed the same thing.

I tried the tips given here (disabling and re-enabling the I2C driver), but it still gives the same output.

I then formatted the SD-card and put a fresh install of raspbian (lite) on it. I ssh'ed into it, enabled i2c in raspi-config, and tried again, but it still shows all addresses in use.

Is this a hardware problem? Is my raspi fried? Or is there still a change this is a software problem which I can solve? All tips are welcome!

2

This is a symptom of SDA being pulled to ground.

Test your GPIO with nothing connected to the extension header.

See https://elinux.org/R-Pi_Troubleshooting#Testing

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  • Thanks. That reveals indeed the following: Write 1 to gpio 2 failed. Pull up on gpio 2 failed.. Does that mean I fried my pi? Is there nothing that I can do about it anymore? – kramer65 Jun 13 at 20:03
  • I am afraid the GPIO is dead (unless you can see anything physical connecting GPIO 2 to ground, such as a solder splash). – joan Jun 13 at 20:06
  • That is sad news, especially since new raspi zero's are hard to find these days. Thanks anyway! – kramer65 Jun 13 at 20:14
  • @kramer65: Like all PIs, the zero has (at least) two I2C busses. you could just switch to the other one (on BCM pins 0 and 1), if all you need is I2C. – PMF Jun 14 at 14:12

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