Gemini Chat Gadget for ESP32-C6-LCD-1.69

This project builds a minimal ESP-IDF application that turns an ESP32-C6-LCD-1.69 board into a Gemini chat gadget. It features on-screen state indicators, speaker beeps, Wi-Fi connectivity, and integration with the Gemini API.

Hardware

• MCU/Board: ESP32-C6 DevKitC-1
• Display: 1.69" ST7789V2, 240x280 resolution, SPI interface
• Default Pins (configurable via Kconfig):
  • MOSI: GPIO7
  • SCLK: GPIO6
  • CS: GPIO5
  • DC: GPIO2
  • RST: GPIO4
  • BL (Backlight): GPIO15
  • BUTTON: GPIO0
  • LED: GPIO8
  • SPEAKER: GPIO25
  • BAT_EN (Battery Enable): GPIO15 (drive HIGH on battery)

Features

• Display Auto-Probe: Automatically detects and configures the ST7789V2 display by trying common rotations, offsets, and SPI clock frequencies.
• UI State Machine: Visual feedback on the LCD for different states: BOOT, CONNECTING, READY, LISTENING, THINKING, SPEAKING, and ERROR.
• Wi-Fi Connectivity: Connects to a specified Wi-Fi network in STA mode.
• Gemini API Integration: Communicates with the Google Gemini API (gemini-1.5-flash model) to generate text responses.
• Audio Feedback: Uses LEDC to generate tones for listening and speaking states, and a short beep for thinking.
• Button Input: A button on GPIO0 triggers a chat cycle.
• Battery Management: Sets BAT_EN (GPIO15) HIGH to enable battery power.

Project Structure

• CMakeLists.txt: Main project CMake file.
• main/CMakeLists.txt: Component CMake file for the main component.
• main/main.c: Main application source code.
• main/Kconfig.projbuild: Defines Kconfig options for Wi-Fi credentials, Gemini API key, and LCD pin overrides.
• sdkconfig.defaults: Default configuration settings, including UART console, FreeRTOS tick rate, and placeholders for Wi-Fi and Gemini API key.

Build and Flash Instructions

1. Set the ESP-IDF Target:

   idf.py set-target esp32c6
   

2. Configure Project Settings: Run menuconfig to set your Wi-Fi SSID, Wi-Fi Password, and Gemini API Key. You can also override default LCD pin assignments here if needed.

   idf.py menuconfig
   

   Navigate to "Application Configuration" to find the Wi-Fi and Gemini API key settings. Navigate to "Application Configuration" -> "LCD Pin Configuration" to adjust pin assignments.

3. Build, Flash, and Monitor: This command will build the project, flash it to your ESP32-C6 board, and open a serial monitor to view logs.

   idf.py build flash monitor
   

Acceptance Criteria

• Upon boot, the LCD should display a color-sweep during the auto-probe routine, followed by the BOOT, CONNECTING, and READY states.
• Pressing the button should initiate the LISTENING state (with a tone), transition to THINKING (with a beep), perform an HTTP POST to the Gemini API, move to SPEAKING (with a tone) while logging the reply, and finally return to the READY state.
• The console logs should clearly show auto-probe attempts and results, Wi-Fi connection status, HTTP status codes, and the extracted Gemini text response.
• The application should handle Wi-Fi or HTTP failures gracefully, transitioning to an ERROR state with appropriate logging.

Dependencies

The project is designed to be lightweight and uses the following ESP-IDF components:

• esp_lcd
• esp_http_client
• cJSON
• esp_wifi
• driver (for GPIO and LEDC)
• esp_timer