esp-idf/examples/peripherals/lcd/spi_lcd_touch/README.md
2024-06-17 12:02:15 +08:00

6.3 KiB

Supported Targets ESP32 ESP32-C2 ESP32-C3 ESP32-C5 ESP32-C6 ESP32-H2 ESP32-P4 ESP32-S2 ESP32-S3

SPI LCD and Touch Panel Example

esp_lcd provides several panel drivers out-of box, e.g. ST7789, SSD1306, NT35510. However, there're a lot of other panels on the market, it's beyond esp_lcd component's responsibility to include them all.

esp_lcd allows user to add their own panel drivers in the project scope (i.e. panel driver can live outside of esp-idf), so that the upper layer code like LVGL porting code can be reused without any modifications, as long as user-implemented panel driver follows the interface defined in the esp_lcd component.

This example shows how to use GC9A01 or ILI9341 display driver from Component manager in esp-idf project. These components are using API provided by esp_lcd component. This example will draw a fancy dash board with the LVGL library.

This example uses the esp_timer to generate the ticks needed by LVGL and uses a dedicated task to run the lv_timer_handler(). Since the LVGL APIs are not thread-safe, this example uses a mutex which be invoked before the call of lv_timer_handler() and released after it. The same mutex needs to be used in other tasks and threads around every LVGL (lv_...) related function call and code. For more porting guides, please refer to LVGL porting doc.

Touch controller STMPE610

In this example you can enable touch controller STMPE610 connected via SPI. The SPI connection is shared with LCD screen.

How to use the example

Hardware Required

  • An ESP development board
  • An GC9A01 or ILI9341 LCD panel, with SPI interface (with/without STMPE610 SPI touch)
  • An USB cable for power supply and programming

Hardware Connection

The connection between ESP Board and the LCD is as follows:

       ESP Board                       GC9A01/ILI9341 Panel + TOUCH
┌──────────────────────┐              ┌────────────────────┐
│             GND      ├─────────────►│ GND                │
│                      │              │                    │
│             3V3      ├─────────────►│ VCC                │
│                      │              │                    │
│             PCLK     ├─────────────►│ SCL                │
│                      │              │                    │
│             MOSI     ├─────────────►│ MOSI               │
│                      │              │                    │
│             MISO     |◄─────────────┤ MISO               │
│                      │              │                    │
│             RST      ├─────────────►│ RES                │
│                      │              │                    │
│             DC       ├─────────────►│ DC                 │
│                      │              │                    │
│             LCD CS   ├─────────────►│ LCD CS             │
│                      │              │                    │
│             TOUCH CS ├─────────────►│ TOUCH CS           │
│                      │              │                    │
│             BK_LIGHT ├─────────────►│ BLK                │
└──────────────────────┘              └────────────────────┘

The GPIO number used by this example can be changed in lvgl_example_main.c. Especially, please pay attention to the level used to turn on the LCD backlight, some LCD module needs a low level to turn it on, while others take a high level. You can change the backlight level macro EXAMPLE_LCD_BK_LIGHT_ON_LEVEL in lvgl_example_main.c.

Build and Flash

Run idf.py -p PORT build flash monitor to build, flash and monitor the project. A fancy animation will show up on the LCD as expected.

The first time you run idf.py for the example will cost extra time as the build system needs to address the component dependencies and downloads the missing components from registry into managed_components folder.

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

...
I (409) cpu_start: Starting scheduler on APP CPU.
I (419) example: Turn off LCD backlight
I (419) gpio: GPIO[2]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (429) example: Initialize SPI bus
I (439) example: Install panel IO
I (439) gpio: GPIO[5]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (449) example: Install GC9A01 panel driver
I (459) gpio: GPIO[3]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (589) gpio: GPIO[0]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (589) example: Initialize touch controller STMPE610
I (589) STMPE610: TouchPad ID: 0x0811
I (589) STMPE610: TouchPad Ver: 0x03
I (599) example: Turn on LCD backlight
I (599) example: Initialize LVGL library
I (609) example: Register display driver to LVGL
I (619) example: Install LVGL tick timer
I (619) example: Starting LVGL task
I (619) example: Display LVGL animation
I (619) example: Display LVGL Meter Widget
...

Troubleshooting

  • Why the LCD doesn't light up?
    • Check the backlight's turn-on level, and update it in EXAMPLE_LCD_BK_LIGHT_ON_LEVEL

For any technical queries, please open an [issue] (https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.