Update README quick start instructions

README.md

@@ -1,6 +1,6 @@
 # RP Pico Display Engine
 
-A lightweight C display engine for `RP2040/RP2350` and `ST7789` displays (SPI + DMA) with an explicit `begin/end paint` frame contract.
+A lightweight C display engine for `RP2040/RP2350` and `ST7789` / `ILI9341` SPI displays (DMA) with an explicit `begin/end paint` frame contract.
 
 ## Features
 
@@ -20,6 +20,34 @@ A lightweight C display engine for `RP2040/RP2350` and `ST7789` displays (SPI +
 - `include/Font/`, `src/Font/` - font data and text rendering
 - `Examples/Thermometr/` - working Pico SDK example project
 
+## Required Environment
+
+- `git`
+- `cmake` version `3.18.4+`
+- build tool supported by CMake (`make` by default on Unix-like systems)
+- `Pico SDK` with `PICO_SDK_PATH` pointing to it
+- ARM toolchain `arm-none-eabi-gcc`
+
+## Supported Displays and Default Wiring
+
+Supported controller backends:
+
+- `DISPLAY_TYPE_ST7789`
+- `DISPLAY_TYPE_ILI9341`
+
+If you do not pass any display-related compile definitions, the library defaults from [src/core/display_driver.h](/home/smikhai/repo/rp_pico_display_engine/src/core/display_driver.h:1) are used:
+
+- Controller: `DISPLAY_TYPE_ST7789`
+- SPI port: `spi0`
+- `MOSI=19`
+- `SCK=18`
+- `CS=17`
+- `DC=22`
+- `RST=13`
+- `BL=12`
+
+These defaults mean: if you build without overriding pins or `DISPLAY_TYPE`, the firmware is meant for an `ST7789` display wired to those RP2040/RP2350 GPIOs.
+
 ## Quick Start
 
 ### 1. Add as a subproject (recommended)
@@ -27,7 +55,27 @@ A lightweight C display engine for `RP2040/RP2350` and `ST7789` displays (SPI +
 The most practical integration pattern is to add this repository (for example, as a git submodule) and build `display_engine` from your main `CMakeLists.txt`.
 You do not have to include all rendering primitives immediately: keep only what you need and uncomment extra modules later.
 
-```cmake
+Create a new project and add this repository as a submodule:
+
+```bash
+mkdir pico_display_app
+cd pico_display_app
+git init
+git submodule add https://github.com/stasenso/rp_pico_display_engine.git external/rp_pico_display_engine
+git submodule update --init --recursive
+mkdir -p src
+```
+
+Make sure `PICO_SDK_PATH` is set:
+
+```bash
+export PICO_SDK_PATH=/absolute/path/to/pico-sdk
+```
+
+Create the root `CMakeLists.txt`:
+
+```bash
+cat > CMakeLists.txt <<'EOF'
 cmake_minimum_required(VERSION 3.18.4)
 include($ENV{PICO_SDK_PATH}/external/pico_sdk_import.cmake)
 
@@ -79,6 +127,46 @@ target_compile_definitions(display_engine PUBLIC
 add_executable(my_app src/main.c)
 target_link_libraries(my_app PRIVATE display_engine)
 pico_add_extra_outputs(my_app)
+EOF
+```
+
+Create `src/main.c`:
+
+```bash
+cat > src/main.c <<'EOF'
+#include "pico/stdlib.h"
+#include "display/display.h"
+#include "display/render/context.h"
+
+int main(void) {
+    stdio_init_all();
+
+    display_config_t cfg = {
+        .width = 320,
+        .height = 240,
+        .buffer_count = 1,
+        .mode = DISPLAY_MODE_SAFE
+    };
+    display_init(&cfg);
+
+    render_ctx_t rc;
+
+    while (1) {
+        uint16_t *buf = display_begin_paint_blocking();
+        render_begin(&rc, buf, 320, 240);
+        render_clear(&rc, RGB16(0, 0, 0));
+        display_end_paint();
+        sleep_ms(16);
+    }
+}
+EOF
+```
+
+Build the project:
+
+```bash
+cmake -S . -B build
+cmake --build build
 ```
 
 ### 2. Change display pins and controller type
@@ -89,7 +177,16 @@ Set these compile definitions on `display_engine`:
 - `DISPLAY_PIN_MOSI`, `DISPLAY_PIN_SCK`, `DISPLAY_PIN_CS`, `DISPLAY_PIN_DC`, `DISPLAY_PIN_RST`, `DISPLAY_PIN_BL`
 - `DISPLAY_TYPE` (`DISPLAY_TYPE_ST7789` or `DISPLAY_TYPE_ILI9341`)
 
-If no definitions are provided, defaults from `src/core/display_driver.h` are used.
+If no definitions are provided, these defaults from [src/core/display_driver.h](/home/smikhai/repo/rp_pico_display_engine/src/core/display_driver.h:1) are used:
+
+- `DISPLAY_TYPE=DISPLAY_TYPE_ST7789`
+- `DISPLAY_SPI_PORT=spi0`
+- `DISPLAY_PIN_MOSI=19`
+- `DISPLAY_PIN_SCK=18`
+- `DISPLAY_PIN_CS=17`
+- `DISPLAY_PIN_DC=22`
+- `DISPLAY_PIN_RST=13`
+- `DISPLAY_PIN_BL=12`
 
 ### 3. Safe mode with a single display loop
 
@@ -208,6 +305,8 @@ draw_string(&rc, 16, 16, L"Cyrillic check", RGB565(255, 255, 255));
 
 ## Build Example (Pico SDK)
 
+If you just want to build the ready-made example from this repository:
+
 ```bash
 cd Examples/Thermometr
 mkdir -p build && cd build
@@ -215,8 +314,30 @@ cmake ..
 cmake --build .
 ```
 
-Display config is set in `Examples/Thermometr/CMakeLists.txt` via `target_compile_definitions(...)`:
-`DISPLAY_TYPE`, `DISPLAY_SPI_PORT`, `DISPLAY_PIN_MOSI`, `DISPLAY_PIN_SCK`, `DISPLAY_PIN_CS`, `DISPLAY_PIN_DC`, `DISPLAY_PIN_RST`, `DISPLAY_PIN_BL`.
+This example builds firmware for the Pico SDK default board unless you set `PICO_BOARD` yourself. The display configuration is set in [Examples/Thermometr/CMakeLists.txt](/home/smikhai/repo/rp_pico_display_engine/Examples/Thermometr/CMakeLists.txt:1):
+
+- Controller: `DISPLAY_TYPE_ILI9341`
+- SPI port: `spi1`
+- `MOSI=15`
+- `SCK=14`
+- `CS=13`
+- `DC=12`
+- `RST=11`
+- `BL=10`
+
+There is also [Examples/EngineDemo/CMakeLists.txt](/home/smikhai/repo/rp_pico_display_engine/Examples/EngineDemo/CMakeLists.txt:1), which defaults to:
+
+- Board: `Pico 2` / `RP2350` (`TARGET_BOARD=pico2_RP2350`)
+- Controller: `DISPLAY_TYPE_ST7789`
+- SPI port: `spi1`
+- `MOSI=15`
+- `SCK=14`
+- `CS=13`
+- `DC=12`
+- `RST=11`
+- `BL=10`
+
+So the produced `.uf2` must be flashed to the board selected by that example's CMake config, and the display must be wired to the pins listed there.
 
 ## API Contract (Important)