QSPI LCD (without RAM) 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 ST77903 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.

How to use the example

Hardware Required

• An ESP32-S3R2 or ESP32-S3R8 development board
• A ST77903 LCD panel, with QSPI interface
• An USB cable for power supply and programming

Hardware Connection

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

       ESP Board                       ST77903 Panel (QSPI)
┌──────────────────────┐              ┌────────────────────┐
│             GND      ├─────────────►│ GND                │
│                      │              │                    │
│             3V3      ├─────────────►│ VCC                │
│                      │              │                    │
│             CS       ├─────────────►│ CS                 │
│                      │              │                    │
│             SCK      ├─────────────►│ CLK                │
│                      │              │                    │
│             D3       ├─────────────►│ IO3                │
│                      │              │                    │
│             D2       ├─────────────►│ IO2                │
│                      │              │                    │
│             D1       ├─────────────►│ IO1                │
│                      │              │                    │
│             D0       ├─────────────►│ IO0                │
│                      │              │                    │
│             RST      ├─────────────►│ RSTN               │
└──────────────────────┘              └────────────────────┘

The LCD parameters and GPIO number used by this example can be changed in lv_port.h. Especially, please pay attention to the vendor specific initialization, it can be different between manufacturers and should consult the LCD supplier for initialization sequence code.

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 (679) example: Turn off LCD backlight
I (684) gpio: GPIO[8]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (693) lvgl_port: Install ST77903 panel driver
I (699) gpio: GPIO[15]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (717) st77903: LCD panel create success, version: 0.3.0
I (1099) lvgl_port: Initialize LVGL library
I (1101) lvgl_port: Install LVGL tick timer
I (1102) lvgl_port: Starting LVGL task
I (1109) example: Turn on LCD backlight
I (1109) example: Display LVGL demos
I (1125) main_task: Returned from app_main()
...

Performance Test

Test Environment

For ESP32-S3R2

For ESP32-S3R8

Description of Buffering Mode

Note: To test the above modes, run the following commands to configure project (take ESP32-S3R8 and Mode4 as an example):

rm -rf build sdkconfig sdkconfig.old
idf.py -D SDKCONFIG_DEFAULTS="sdkconfig.defaults.psram_octal_ddr;sdkconfig.test.direct_mode" reconfigure

Average FPS using ESP32-S3R2

Average FPS using ESP32-S3R8

Troubleshooting

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