Integrating Waveshare ESP32-S3-Touch-LCD-7B With ESPHome For Enhanced Control

Jul 8, 2025 by Jeany 78 views

Waveshare ESP32-S3-Touch-LCD-7B Support Discussion

Introduction

The Waveshare ESP32-S3-Touch-LCD-7B is a new iteration of the ESP32-S3 board that comes with a built-in 7-inch display. This enhanced model boasts a higher resolution of 1024x600 and, crucially, introduces the ability to control screen brightness. Prior models relied on a CH422G IO extender to manage the LCD backlight enable pin. However, this new model has transitioned to a different chip, marking a significant upgrade in its capabilities. This article delves into the intricacies of integrating the Waveshare ESP32-S3-Touch-LCD-7B with ESPHome, addressing the challenges and potential solutions for leveraging its advanced features.

This article aims to provide a comprehensive overview of the Waveshare ESP32-S3-Touch-LCD-7B, focusing on its integration with ESPHome. We will discuss the new features, the challenges in adapting existing configurations, and potential solutions for fully utilizing the board's capabilities. Whether you're an experienced ESPHome user or new to the platform, this guide will help you understand the nuances of this new hardware and how to make the most of it.

Problem Description: Integrating Brightness Control and Battery Monitoring

The primary challenge lies in adapting existing ESPHome configurations to accommodate the new chip used for backlight control. Previous Waveshare models utilized a CH422G IO extender, but the ESP32-S3-Touch-LCD-7B employs a CH32V003 microcontroller unit (MCU). This shift necessitates a different approach to controlling the screen brightness. While Waveshare provides example code demonstrating interaction with the PWM backlight via their demo LVGL_UI, integrating this functionality into ESPHome requires a deeper understanding of the hardware and software interfaces.

The core issue is the change in hardware for controlling the LCD backlight. The transition from the CH422G IO extender to the CH32V003 MCU means that existing ESPHome configurations that worked seamlessly with previous models are no longer directly applicable. The example code provided by Waveshare offers a glimpse into how to interact with the new chip, but translating this into a functional ESPHome component is a complex task. This involves understanding the communication protocol between the ESP32-S3 and the CH32V003, as well as implementing the necessary drivers within the ESPHome framework.

In addition to brightness control, the new chip also handles battery voltage monitoring, which presents another opportunity for integration with ESPHome. Accurately monitoring battery voltage can provide valuable insights into the device's power consumption and battery health. This feature can be particularly useful for battery-powered applications, allowing for proactive management of power resources and preventing unexpected shutdowns. Integrating battery voltage monitoring into ESPHome would require understanding the interface between the CH32V003 and the voltage sensing circuitry, as well as implementing the appropriate sensors and data processing within ESPHome.

Use Case and Alternatives Explored

The main use case for this integration is to fully utilize the capabilities of the Waveshare ESP32-S3-Touch-LCD-7B within a home automation or IoT environment managed by ESPHome. This includes controlling the screen brightness dynamically, allowing for adjustments based on ambient lighting conditions or user preferences. The ability to dim the screen at night, for example, can enhance user experience and reduce power consumption. Another crucial use case is monitoring the battery voltage, which is essential for battery-powered applications to ensure optimal performance and prevent unexpected power outages.

Without proper integration, users are limited to a fixed brightness level, which can be suboptimal in various lighting conditions. This lack of control can lead to eye strain in low-light environments and excessive power consumption when the screen is unnecessarily bright. Similarly, the inability to monitor battery voltage can lead to unpredictable device behavior and potential data loss in battery-powered applications. By integrating these features into ESPHome, users can create a more seamless and efficient user experience, tailored to their specific needs and environment.

Alternative solutions explored include attempting to adapt the existing CH422G-based configurations, but these proved ineffective due to the fundamental hardware change. Another approach considered was to directly implement the example code provided by Waveshare as an external component within ESPHome. However, this method presented challenges due to the complexity of the code and the need to understand the underlying communication protocols. A native driver implementation within ESPHome would provide the most robust and user-friendly solution, but it requires a significant development effort.

Detailed Analysis of the Hardware and Software

The Waveshare ESP32-S3-Touch-LCD-7B features a 7-inch capacitive touchscreen display with a resolution of 1024x600 pixels. The display is driven by the ESP32-S3 microcontroller, which provides ample processing power and connectivity options. The key difference in this model is the use of the CH32V003 MCU for handling backlight control and battery voltage monitoring, replacing the CH422G IO extender used in previous versions. This change necessitates a new driver implementation within ESPHome to take full advantage of the board's capabilities.

The CH32V003 is a RISC-V-based microcontroller known for its low power consumption and versatility. It communicates with the ESP32-S3 via a serial interface, likely SPI or I2C. Understanding the specific communication protocol is crucial for developing a compatible driver. The example code provided by Waveshare offers valuable insights into the communication protocol and the registers that need to be accessed to control the backlight and read the battery voltage. Analyzing this code is a critical step in the integration process.

The PWM backlight control allows for fine-grained adjustment of the screen brightness, enabling users to optimize the display for various lighting conditions. The battery voltage monitoring circuit is connected to the CH32V003, providing a means to track the battery's state of charge. This information can be used to implement low-battery warnings, optimize power consumption, and prevent data loss due to unexpected shutdowns. Integrating these features into ESPHome requires a combination of hardware understanding, software development, and a thorough understanding of the ESPHome framework.

Integrating with ESPHome: Proposed Solutions and Steps

To integrate the Waveshare ESP32-S3-Touch-LCD-7B fully with ESPHome, a multi-faceted approach is required. The first step involves developing a custom component for ESPHome that can communicate with the CH32V003 microcontroller. This component will act as a bridge between ESPHome and the hardware, allowing users to control the backlight and monitor battery voltage.

The development process can be broken down into the following key steps:

Protocol Analysis: Decipher the communication protocol between the ESP32-S3 and the CH32V003. This involves analyzing the example code provided by Waveshare, as well as the hardware schematics. Understanding the registers and commands used to control the backlight and read the battery voltage is crucial.
Driver Implementation: Develop an ESPHome component that can send and receive data via the identified communication protocol. This component will need to handle the low-level details of serial communication, as well as the specific commands required by the CH32V003.
Backlight Control: Implement functionality within the component to control the PWM backlight. This involves writing to the appropriate registers on the CH32V003 to set the desired brightness level. An ESPHome slider or number entity can be used to expose this functionality to the user.
Battery Voltage Monitoring: Implement functionality to read the battery voltage from the CH32V003. This involves reading the appropriate registers and converting the raw data into a voltage reading. An ESPHome sensor entity can be used to display the battery voltage.
Testing and Validation: Thoroughly test the component to ensure that the backlight control and battery voltage monitoring are working correctly. This involves varying the brightness level and monitoring the battery voltage under different conditions.

Code Snippets and Example Configurations

The provided ZIP file (test32-s3-waveshare7b.zip) contains an example configuration that worked with the previous Waveshare model. While this configuration will not directly work with the ESP32-S3-Touch-LCD-7B due to the hardware changes, it can serve as a starting point for a new configuration. The key areas that need to be modified are the LCD backlight control and the battery voltage monitoring sections.

To illustrate the concept, consider the following snippet for implementing backlight control (this is a conceptual example and may require adjustments based on the specific communication protocol):

# Example ESPHome configuration snippet (conceptual)
external_components:
  - source: # Path to custom component
    components: [ ch32v003_controller ]

ch32v003_controller:
  id: ch32v003_controller
  # Configuration parameters (e.g., SPI or I2C pins)

light:
  - platform: custom
    name: "LCD Backlight"
    lambda: |- 
      id(ch32v003_controller).set_backlight(x);
    children:
      - platform: output
        output: backlight_pwm

output:
  - platform: esp32_pwm
    id: backlight_pwm
    pin: GPIO45 # Example GPIO pin
    frequency: 1000 Hz

This snippet demonstrates how a custom component could be used to control the backlight. The ch32v003_controller component would handle the communication with the CH32V003, and the light platform would provide a user-friendly way to control the brightness. The lambda function would translate the brightness value into a command that the CH32V003 understands.

Similarly, battery voltage monitoring could be implemented using a sensor:

sensor:
  - platform: custom
    name: "Battery Voltage"
    lambda: |- 
      return id(ch32v003_controller).get_battery_voltage();
    unit_of_measurement: V
    device_class: voltage
    state_class: measurement
    update_interval: 60s

This snippet shows how a custom sensor could be used to read the battery voltage. The get_battery_voltage() function within the ch32v003_controller component would read the voltage from the CH32V003 and return the value.

Additional Context and Resources

The provided links to the Waveshare wiki, demo code, and schematics are invaluable resources for integrating the ESP32-S3-Touch-LCD-7B with ESPHome. The demo code provides a working example of how to interact with the CH32V003, while the schematics offer detailed information about the hardware connections and components. These resources are essential for understanding the underlying hardware and software and developing a robust ESPHome component.

Specifically, the LVGL_UI demo (https://www.waveshare.com/wiki/ESP32-S3-Touch-LCD-7B#16_LVGL_UI) contains the example of interacting with the PWM backlight, which is a crucial piece of information for implementing brightness control in ESPHome. The demo ZIP file (https://files.waveshare.com/wiki/ESP32-S3-Touch-LCD-7B/ESP32-S3-Touch-LCD-7B-Demo.zip) includes the source code for the demo, which can be analyzed to understand the communication protocol and the commands used to control the CH32V003.

The schematic diagram (https://files.waveshare.com/wiki/ESP32-S3-Touch-LCD-7B/ESP32-S3-Touch-LCD-7B-Schematic.pdf) provides detailed information about the hardware connections, including the pins used for communication between the ESP32-S3 and the CH32V003. This information is essential for configuring the ESPHome component and ensuring that the communication is working correctly.

Conclusion

Integrating the Waveshare ESP32-S3-Touch-LCD-7B with ESPHome presents a unique set of challenges and opportunities. The transition to the CH32V003 MCU for backlight control and battery voltage monitoring requires a new approach to driver development. However, by leveraging the resources provided by Waveshare and following a structured development process, it is possible to create a robust ESPHome component that fully utilizes the board's capabilities. This will enable users to dynamically control screen brightness, monitor battery voltage, and create a more seamless and efficient user experience within their home automation or IoT environments.

By addressing the problem of integrating the new brightness control and battery monitoring features, users can unlock the full potential of the Waveshare ESP32-S3-Touch-LCD-7B. This not only enhances the functionality of the device but also provides valuable insights into its power consumption and battery health, leading to a more reliable and user-friendly experience. The steps outlined in this article provide a roadmap for developers and enthusiasts looking to contribute to the ESPHome ecosystem and make this powerful hardware platform even more accessible.