<![CDATA[AMOLED S3 Touch - I2C port interference with QWIIC port?]]>Does the touch display use the same I2C interface as is on the STEMMA / QWIIC connector?

I am getting some random I2C error reading some devices.

By the schematic, it appears that that is the case. I am using a mutex in FreeRTOS to access the I2C port between several tasks. Is there a way to make sure lvgl uses the same mutex before accessing the port?

I am trying to solve it by adding a Take and Give for my mutex around each access to lv_task_handler(), but not sure if that is the way to go

void do_lv_task_handler() {
  xSemaphoreTake(I2C_Mutex, portMAX_DELAY);
  lv_task_handler();
  xSemaphoreGive(I2C_Mutex);
}
]]>https://www.community.lilygo.cc/topic/995/amoled-s3-touch-i2c-port-interference-with-qwiic-portRSS for NodeSun, 12 Apr 2026 17:17:49 GMTMon, 03 Jun 2024 01:42:36 GMT60<![CDATA[Reply to AMOLED S3 Touch - I2C port interference with QWIIC port? on Thu, 13 Jun 2024 20:00:56 GMT]]>@teastain2

Thanks, I realize that I can change the definitions of Wire to the other pin, but then would the Touch display not function appropriately?

I would prefer to define GPIO2 and GPIO3 as Wire1 and not Wire, and have the touch display use that interface. I would then define Wire as the new pins (as per your example above).

Is there a software option to do this? I am using some libraries that are hardcoded to Wire, and don't want to manually change them myself.

If not possible, the Mutex method around the lv_task_handler() seems to work well - the board has been running for about 2 weeks with no issues, and no bad data.

]]>https://www.community.lilygo.cc/post/1841https://www.community.lilygo.cc/post/1841Thu, 13 Jun 2024 20:00:56 GMT<![CDATA[Reply to AMOLED S3 Touch - I2C port interference with QWIIC port? on Mon, 03 Jun 2024 04:42:37 GMT]]>U0RXD U0TXD (44/43) are the RS232 Serial connections...and... are the standard I2C ports on LilyGO T-Display S3 and T-HMI and several others.
As you may know you inform the compiler with

Wire.begin(43, 44);

I don't have a LilyGO T-Display S3 AMOLED Touch here!
So I suppose the 6pin is the Touch and is between the Display and the board???

You should check here:
https://github.com/Xinyuan-LilyGO/LilyGo-AMOLED-Series/issues/9#issuecomment-1888466187

And perhaps raise your own issue?
@lewisxhe is very good but very busy
cheers, Terry

]]>https://www.community.lilygo.cc/post/1773https://www.community.lilygo.cc/post/1773Mon, 03 Jun 2024 04:42:37 GMT<![CDATA[Reply to AMOLED S3 Touch - I2C port interference with QWIIC port? on Mon, 03 Jun 2024 02:48:03 GMT]]>@rs77can

I was lopoking at these 2 pieces of the schematic

touch.jpg Qwiic.jpg

The top is the touch interface, and the bottom is the Qwiic port - they both seem to be using the same GPIO2/3

U0RXD U0TXD (44/43) are the RS232 Serial connections - no?

]]>https://www.community.lilygo.cc/post/1772https://www.community.lilygo.cc/post/1772Mon, 03 Jun 2024 02:48:03 GMT<![CDATA[Reply to AMOLED S3 Touch - I2C port interference with QWIIC port? on Mon, 03 Jun 2024 02:30:41 GMT]]>@rs77can AMOLED S3 Touch has two qwiic ports,
GPIO 2,3 and
GPIO 43, 44.
I don't see a conflict on the schematic!
https://github.com/Xinyuan-LilyGO/LilyGo-AMOLED-Series/blob/master/schematic/T-Display-S3-AMOLED-Touch.pdf

Screenshot 2024-06-02 at 10.29.06 PM.jpg

]]>https://www.community.lilygo.cc/post/1771https://www.community.lilygo.cc/post/1771Mon, 03 Jun 2024 02:30:41 GMT