Merge branch 'feat/lcd_example_add_rd' into 'master'

docs(lcd): update rd pin description for i80_controller example

Closes IDFGH-17289

See merge request espressif/esp-idf!46069
This commit is contained in:
morris
2026-02-26 18:03:56 +08:00
@@ -37,7 +37,7 @@ The connection between ESP Board and the LCD is as follows:
| | | |
| DATA[0..7] |<------------>| DATA[0..7] |
| | | |
| PCLK +------------->| PCLK |
| PCLK +------------->| PCLK (WR) |
| | | |
| CS +------------->| CS |
| | | |
@@ -47,9 +47,15 @@ The connection between ESP Board and the LCD is as follows:
| | | |
| BK_LIGHT +------------->| BCKL |
| | | |
| 3V3 +------------->| RD |
| | | |
+-------------+ +----------------+
```
> [!IMPORTANT]
> The 8080 interface also has an **RD** pin. The RD line must be **held high** when idle. (Connect to 3V3 or use pull-up resistors)
Especially, please pay attention to the binary signal level used to turn the LCD backlight on, some LCD modules need a low level to turn it on, while others require a high level. You can change the backlight level macro `EXAMPLE_LCD_BK_LIGHT_ON_LEVEL` in [i80_controller_example_main.c](main/i80_controller_example_main.c).
### Build and Flash
@@ -98,6 +104,8 @@ This example supports two ways of reading images
## Troubleshooting
* **Garbled or random display, or different image on each boot:** If your LCD has an RD pin with no internal pull-up, it must be held high. You can directly connect RD to the 3V3 or use a pull-up resistor.
* Can't get a stable UI when `EXAMPLE_LCD_I80_COLOR_IN_PSRAM` is enabled.
This is because of the limited PSRAM bandwidth, compared to the internal SRAM. You can either decrease the PCLK clock `EXAMPLE_LCD_PIXEL_CLOCK_HZ` from the menuconfig or increase the PSRAM working frequency `SPIRAM_SPEED` from the KConfig (e.g. **Component-config** -> **ESP PSRAM** -> **PSRAM config** -> **Set PSRAM clock speed**) or decrease the FPS in LVGL configuration. In addition, enabling `SPIRAM_XIP_FROM_PSRAM` can help increase the PCLK frequency when the Frame Buffer is allocated from the PSRAM.