I2C write failed in gt911 worker

[stc1988]

Build environment: macOS
Moddable SDK version: 8.3.1
Target device: Moddable Six

Steps to Reproduce

1. Build and install the app examples/piu/drag
2. An error occurs during the drag operation.

/Users/satoshi/Projects/moddable/modules/io/i2c/esp32/_i2c.c (350) # Break: Error: write failed (in write)!

[phoddie]

Alas, we're not seeing an exception here. We tried on two different development machines with two different Moddable Six devices.

cd $MODDABLE/examples/piu/drag
mcconfig -d -m -p esp32/moddable_six

A common reason for I²C failures is an incorrect I²C bus address. On Moddable Six, the host provider probes for the address (0x14 or 0x5D) at start-up and the result is propagated to the gt911 driver, which sends it on to the gt911 worker. That code path looks correct, but perhaps there's something I'm missing?

[stc1988]

Since it’s occurring in onSample while dragging rather than at startup, it doesn’t seem to be caused by an incorrect bus address.
https://github.com/user-attachments/assets/56a17c90-4918-45e0-b3ee-aa1afca3a984

[stc1988]

I saw logs like the following in the instrumented build.

E (31232) i2c.master: I2C bus is still busy but software timeout detected
XS abort: unhandled exception writeRead failed

[phoddie]

That new information means that the I²C address is correct. The GT911 driver uses the default I²C timeout, which is 400 ticks (which is 400 ms on a Moddable SDK build). That's more than long enough for the I²C transaction to complete.

Looking back on recent changes, one stands out. The I²C bus speed was bumped from 200 kHz to 400 kHz. That exceeds what the data sheet recommends. It may be that it works reliably on some chips or physical environments but not others. Would you try changing that back to 200 kHz to see if that makes a difference? Thank you.

[stc1988]

I tried changing it back to 200 kHz, but I didn't notice any difference.

[phoddie]

Thank you for trying. Unfortunately, without being able to see the issue and without further detail, there's nothing more I can think to do. If you have any further insights, please us know.