fix(fw): 4.3C IO expander bootloop — use direct register protocol#3
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The board's IO expander (schematic U10) is a custom MCU expander, NOT a real
CH422G: it has SWDIO/PWM/ADC pins and speaks a register-pointer protocol at
I2C 0x24 (reg 0x02 = direction mask, reg 0x03 = output latch). The vendored
Espressif esp_io_expander_ch422g driver uses the real-CH422G multi-address
protocol (0x23/0x38/...) which NACKs on this board -> esp_io_expander_new_i2c
aborts in board_display_init -> boot loop, screen never comes up.
Fix: talk to the expander directly with two I2C register writes (matches
Waveshare's reference io_extension, verified on hardware). Remove the vendored
esp_io_expander*.{c,h} + stub header. Silence the legacy-i2c deprecation notice.
Verified on hardware: boots past IO expander, RGB+LVGL init, TinyUSB composite
enumerates as 'TokenPulse' (CDC /dev/cu.usbmodemTP_00011 + HID), no more abort.
…ffer The static dashboard only produced dirty regions for the first frame, so with avoid_tearing's two RGB framebuffers only one ever got painted; the panel flashed white whenever it swapped to the never-drawn second framebuffer. Set full_refresh so every frame repaints the whole screen -> both framebuffers always hold the complete image. Compile-verified.
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Symptom
Flashed 4.3C firmware boot-loops; screen never lights up. Serial log:
Root cause
The board's IO expander (schematic U10) is not a real CH422G — it's a custom MCU-based expander (it exposes SWDIO/PWM/ADC pins, which a CH422G lacks). It speaks a simple register-pointer protocol at I2C 0x24 (reg
0x02= direction mask, reg0x03= output latch). The vendored Espressifesp_io_expander_ch422gdriver uses the real-CH422G multi-address protocol (writes to 0x23/0x38/…), which NACKs here →esp_io_expander_new_i2c_ch422gaborts inboard_display_init→ boot loop.(The Task-2 review recommended keeping the vendored driver over a hand-rolled one; on real hardware that was the wrong call — the vendored driver doesn't match this board's expander.)
Fix
Talk to the expander directly with two I2C register writes (matches Waveshare's reference
io_extension, which the knowledge base documents as working on this exact board). Remove the vendoredesp_io_expander*.{c,h}+ stub header. Also silence the intentional legacy-i2c deprecation notice.Verified on hardware
Boots past the IO expander → RGB + LVGL init → TinyUSB composite enumerates as
TokenPulse/Espressifwith CDC/dev/cu.usbmodemTP_00011+ HID. No more abort. (Visual render + end-to-end data push still to be eyeballed.)