From 679b7ade121a77f78dcab124daf45b47c4a40499 Mon Sep 17 00:00:00 2001 From: Chen Chen Date: Thu, 26 Feb 2026 11:45:13 +0800 Subject: [PATCH] docs(lcd): update rd pin description for i80_controller example Closes https://github.com/espressif/esp-idf/issues/18277 --- examples/peripherals/lcd/i80_controller/README.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/examples/peripherals/lcd/i80_controller/README.md b/examples/peripherals/lcd/i80_controller/README.md index 31262b6dfd..34148ba271 100644 --- a/examples/peripherals/lcd/i80_controller/README.md +++ b/examples/peripherals/lcd/i80_controller/README.md @@ -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.