Home
Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Home
Forums
Main category
Main forum
i2c transfer timed out
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="f18m" data-source="post: 532" data-attributes="member: 171"><p>Short update on this: the I2C bus lockup happened also today.</p><p>I don't know how it's possible but even after several power-cycles, the I2C remains locked... at reboot the Raspberry keeps complaining:</p><p></p><p></p><p></p><p>I'm not sure how's that possible. Nothing is wired on the pins of the I2C appearing on the GPIO connector. No change in wiring has happened between yesterday (during which the software polled the I2C bus at 1Hz for the whole day just fine) and today (when the I2C bus lockup happened).</p><p>And how's possible that after a power cycle where I cut the power off, watch all LEDs turn off, and then provide again the power, the I2C bus remains locked up? I have no idea.</p><p></p><p></p><p>The 16pind compiled utility (compiled from C) does not work either. The i2cdetect utility has timeouts. </p><p>Nothing seems to work; every attempt to use I2C results in another line in the dmesg log:</p><p></p><p></p><p>I start to believe that Raspberry Model B+ I2C is seriously bugged. Lots of people on the web have found the "I2C clock stretching" bug, best described by <a href="https://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html" target="_blank">https://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html</a> </p><p>I'm not sure if the clock stretching is done by the IO expander used by the hat.<strong> Is the hat v2.0 using the AWINIC AW9523BTQR as I/O expander?</strong></p><p>I looked in the datasheet and clock stretching is not mentioned.</p><p></p><p>Anyway I'm considering replacing that old raspberry with a newer Raspberry Model 4... at this page: <a href="https://hackaday.com/2022/02/01/did-you-know-that-the-raspberry-pi-4-has-more-spi-i2c-uart-ports/" target="_blank">https://hackaday.com/2022/02/01/did-you-know-that-the-raspberry-pi-4-has-more-spi-i2c-uart-ports/</a> they mention that at least the clock-stretching bug has been fixed and generally speaking the I2C kernel driver is probably a bit different.</p><p></p><p>I also believe that this hat has probably been used mostly with recent raspberry models.... <strong>which model of Raspberry do you use to test/QA/validate the hats like the 16LV digital inputs HAT ?</strong></p><p></p><p>thanks</p></blockquote><p></p>
[QUOTE="f18m, post: 532, member: 171"] Short update on this: the I2C bus lockup happened also today. I don't know how it's possible but even after several power-cycles, the I2C remains locked... at reboot the Raspberry keeps complaining: I'm not sure how's that possible. Nothing is wired on the pins of the I2C appearing on the GPIO connector. No change in wiring has happened between yesterday (during which the software polled the I2C bus at 1Hz for the whole day just fine) and today (when the I2C bus lockup happened). And how's possible that after a power cycle where I cut the power off, watch all LEDs turn off, and then provide again the power, the I2C bus remains locked up? I have no idea. The 16pind compiled utility (compiled from C) does not work either. The i2cdetect utility has timeouts. Nothing seems to work; every attempt to use I2C results in another line in the dmesg log: I start to believe that Raspberry Model B+ I2C is seriously bugged. Lots of people on the web have found the "I2C clock stretching" bug, best described by [URL]https://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html[/URL] I'm not sure if the clock stretching is done by the IO expander used by the hat.[B] Is the hat v2.0 using the AWINIC AW9523BTQR as I/O expander?[/B] I looked in the datasheet and clock stretching is not mentioned. Anyway I'm considering replacing that old raspberry with a newer Raspberry Model 4... at this page: [URL]https://hackaday.com/2022/02/01/did-you-know-that-the-raspberry-pi-4-has-more-spi-i2c-uart-ports/[/URL] they mention that at least the clock-stretching bug has been fixed and generally speaking the I2C kernel driver is probably a bit different. I also believe that this hat has probably been used mostly with recent raspberry models.... [B]which model of Raspberry do you use to test/QA/validate the hats like the 16LV digital inputs HAT ?[/B] thanks [/QUOTE]
Verification
Post reply
Home
Forums
Main category
Main forum
i2c transfer timed out
Top