<![CDATA[PortA i2c unit not recognized in Core2 when stacked onto Servo2?]]>Hi,

I am using ExtIO2 unit with Servo2 stacked beneath Core2, but the Extio2 module is not recognized ("extio Connect Error").
I am using the newest Extio2 library on with extio.begin(&Wire, 32, 33, 0x45) and beginning M5.begin(true,false,true,false,kMBusModeInput). This pins shouldn't be a conflict, as Servo2 is running by default on the internal bus wire1.begin(21,22).

The Extio2 is recognized instantly at portA when used without the Servo2.

Anyone has an idea what could cause this?

]]>https://community.m5stack.com/topic/4742/porta-i2c-unit-not-recognized-in-core2-when-stacked-onto-servo2RSS for NodeSun, 19 Apr 2026 13:52:05 GMTFri, 21 Oct 2022 23:14:26 GMT60<![CDATA[Reply to PortA i2c unit not recognized in Core2 when stacked onto Servo2? on Sun, 23 Oct 2022 11:22:39 GMT]]>Hello @swiminthesky

no worries. Thank you for reporting back. I am glad it now works for you.

Thanks
Felix

]]>https://community.m5stack.com/post/19081https://community.m5stack.com/post/19081Sun, 23 Oct 2022 11:22:39 GMT<![CDATA[Reply to PortA i2c unit not recognized in Core2 when stacked onto Servo2? on Sun, 23 Oct 2022 11:11:51 GMT]]>Yes, it seems to be a hardware problem! I switched the Servo2 module and everything works perfectly and the i2c connections over port A runs without any interruptions. Thanks Felix @felmue and sorry for bothering!

]]>https://community.m5stack.com/post/19080https://community.m5stack.com/post/19080Sun, 23 Oct 2022 11:11:51 GMT<![CDATA[Reply to PortA i2c unit not recognized in Core2 when stacked onto Servo2? on Sat, 22 Oct 2022 14:22:41 GMT]]>Hello @swiminthesky

hmm, not sure what is going on.

Maybe the Servo2 library still uses Wire somewhere internally?

Could it be a mechanical problem?

BTW: my I2CScanInternalAndAllPorts is for M5Paper - I have not tested it on other M5Stack devices.

Thanks
Felix

]]>https://community.m5stack.com/post/19072https://community.m5stack.com/post/19072Sat, 22 Oct 2022 14:22:41 GMT<![CDATA[Reply to PortA i2c unit not recognized in Core2 when stacked onto Servo2? on Sat, 22 Oct 2022 12:41:57 GMT]]>Thanks Felix @felmue,

external power is used. Servo2 example (on Wire1.begin(21, 22);) also works like a charm.

I used both these M5 i2c scanners I2CScanInternalAndAllPorts and I2C_Tester, but no I2C devices are found.

But after removing Servo2 the device is instantly found correctly!

(Also: I used PaHub on PortA inbetween and Extio2 is also instantly found when Servo2 is not stacked)

0_1666436715971_WIN_20221022_12_27_01_Pro.jpg
(ext power is not used for the picture, the Bottom2 also didn't make a difference afaik)

]]>https://community.m5stack.com/post/19068https://community.m5stack.com/post/19068Sat, 22 Oct 2022 12:41:57 GMT<![CDATA[Reply to PortA i2c unit not recognized in Core2 when stacked onto Servo2? on Sat, 22 Oct 2022 05:19:35 GMT]]>Hello @swiminthesky

I assume you are using an external power supply for the Servo2 module as suggested here. I also assume that the Servo2 module on its own works fine, correct?

Are there any errors in the debug output? Maybe I2C related.

Thanks
Felix

]]>https://community.m5stack.com/post/19064https://community.m5stack.com/post/19064Sat, 22 Oct 2022 05:19:35 GMT