lvgl-integration

# LVGL Integration ## Overview Use this skill to integrate LVGL by proving four porting contracts: display flush, input device read, tick/timebase, and memory/draw buffer configuration. UI bugs often come from driver timing or buffer ownership, not widget logic. ## When To Use Use this skill when: - The user wants to add or debug LVGL/littlevGL on an MCU or embedded Linux display. - The issue involves blank screen, wrong colors, tearing, touch offset, slow refresh, memory faults, tick handling, or display flush callbacks. - The project has display, touch, encoder, keypad, RTOS, or DMA/cache constraints. Do not use this skill when the display hardware has no proven signal. Use `hardware-interface-debug` first. ## First Questions Ask for: - LVGL major version and target platform. - Display controller, resolution, color format, interface, and framebuffer/draw buffer strategy. - Input devices: touch, buttons, encoder, keypad, or none. - Tick source and `lv_timer_handler` scheduling. - RAM budget, heap policy, RTOS use, DMA/cache involvement. - Current symptom and minimal screen test result. ## Integration Checklist 1. Bring up display flush. Fill the screen with solid colors before creating complex widgets. 1. Configure draw buffers. Buffer size, color format, stride, and cache/DMA policy must match the display path. 1. Provide a reliable tick. LVGL needs a monotonic tick and regular handler execution. 1. Add input after display. Touch/encoder/keypad sho...