Unable to write i2c device

General Discussion
1

Basic Information:

Printer Model: Zero G Mercury
MCU / Printerboard: BTT SKR 3 EZ
k [klippy-1.log|attachment](upload://z3mnJHfwtpRWz0t9hA8TzePPxYS.log) (3.8 MB) lippy.log

Fill out above information and in all cases attach your klippy.log file. Pasting your printer.cfg is not needed

Describe your issue:

trying to run input shaper after having previous issues with the numpy and having a fresh install and off octoprint onto mainsail

i have tried to run MEASURE_AXES_NOISE

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and trying to run TEST_RESONANCES AXIS=X

i get this error after completing all of the nessicary install instructions for the sensor i am using

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2

Typically this has one of the following reasons:

  • Wiring issue
  • Wrong pins chosen on the board
  • Not having enabled I2C or wrong baud rate set. Ref to enabling-i2c
3

One addition thing that can come in handy:

On Linux you can use the i2cdetect command to scan your i2c bus:

  • i2cdetect -l will list all available i2c buses
  • i2cdetect -y 0 will list all devices on the first bus (you need to identify the correct bus you have chosen)
  • Depending on the MPU type you need to see an output of 68 or 70 or 71 or 73 or 74 somewhere in the output of the above command. These are the device IDs of the supported MPU chips.

Example:
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If you do not get such output something is wrong in your setup.

4

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what am i doing wrong here

5

https://www.google.com/search?q=i2cdetect+command+not+found

1 Like
6

OKay i can get the command to work
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let me see if i can get input shaper to work.

with sensor plugged in
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8

Please just drop the klippy.log here showing the error. These screenshots just add clutter.

Unfortunately I have no further idea:

  • I can confirm the MPUs to be working since I’m using one myself successfully with an RPi 3B, OPi 3 LTS and a RPi Pico
  • Basically it seems to be working but it is quickly loosing connection on your side
  • Either a half dead chip or some wonky wiring
9

I think it’s helpful to note that i2c devices are picky about cable length, running anything longer than a metre can cause this issue!

Ask me how I know :woozy_face: