Data_Exchange

📡 About
This Proof of Concept (PoC) demonstrates a transparent bridge between wired UART communication and the wireless ESP-NOW protocol.

It creates a simple, unidirectional data pipeline using three microcontrollers:

• Generic MCU → UART → ESP32-C6 (bridge) → ESP-NOW → ESP32 (receiver)

Raw ASCII strings sent from the source are forwarded wirelessly and displayed (with sender MAC) on the receiver.

graph LR
    A[Source MCU<br>e.g. Arduino / STM32] -- UART --> B[Bridge<br>ESP32-C6-DevKitM-1<br>ESP-IDF]
    B -- ESP-NOW --> C[Receiver<br>ESP32 WROOM-32<br>Arduino / PlatformIO]

Loading

🛠️ Hardware Requirements

1. Source: Any microcontroller sending plain text strings over UART (9600–115200 baud typical).

2. Bridge – ESP32-C6: Board: ESP32-C6-DevKitM-1 Framework: ESP-IDF v5.x Responsibilities: Receive data via UART Forward payload using ESP-NOW Cycle onboard WS2812 LED color (R → G → B) on each boot using NVS (persistence) Precise WS2812 control via RMT peripheral

3. Receiver – ESP32: Board: ESP32 DevKit / NodeMCU-32S / etc. Framework: Arduino + PlatformIO Responsibilities: Listen for ESP-NOW packets Print sender MAC address + received payload to Serial

🧩 Key Features

• Protocol Bridging: Seamlessly converts standard UART serial streams (wired) to ESP-NOW frames (wireless).

• NVS State Persistence: The ESP32-C6 utilizes Non-Volatile Storage (NVS) to remember its configuration state across reboots.

• Demo: Upon every reset, the C6 cycles its boot indicator color (Red → Green → Blue → Yellow → Purple) and saves the index to flash.

• Visual Feedback (RMT): Utilizes the RMT peripheral to drive an onboard addressable RGB LED (WS2812), providing real-time status of data transmission.

• Hybrid Frameworks: Demonstrates interoperability between ESP-IDF (running on the C6) and Arduino (running on the Receiver).

🔌 Hardware & Pinout

Pin	Function	Description
GPIO17 (ESP32-C6)	UART RX	Connect to Source MCU TX
GPIO8 (ESP32-C6)	WS2812	DataOnboard RGB LED (usually pre-connected)
PA2 (STM32-F407G)	UART TX	Connected to Bridge MCU RX
3V3/GND	Power/GND	Share ground with source MCU

**Note: Most ESP32-C6 dev boards already connect the onboard WS2812 to GPIO8. Double-check your board schematic.

📥 Installation & Usage

1. Bridge – ESP32-C6 (ESP-IDF)

# 1. Clone or download the project
git clone https://github.com/yourusername/Data_Exchange.git
cd Data_Exchange/Sender/ESP-IDF

# 2. Set target (only needed once)
idf.py set-target esp32c6

# 3. Optional: configure project settings
idf.py menuconfig

# 4. Build & flash & monitor
idf.py -p /dev/ttyUSB0 flash monitor
#               ↑ replace with your port

After flashing, the LED should change color on every reset (proof of NVS working).

2. Receiver – ESP32 (Arduino / PlatformIO)

# Open the Receiver/Arduino folder in VS Code with PlatformIO extension

# Then either:
# • Click Upload (→) in PlatformIO toolbar
# • or run in terminal:
pio run --target upload

Open the Serial Monitor (115200 baud) to see incoming messages.

🌳 Project Structure

Data_Exchange/
├── Source/
│   └── STM32CubeIDE/
│       ├── Core/                   # Auto-generated HAL + startup code
│       │   ├── Inc/
│       │   └── Src/
│       │       └── main.c          # User code: UART transmit example
│       ├── Drivers/                # STM32 HAL + CMSIS
│       ├── .ioc                    # STM32CubeMX configuration file
│       └── STM32xxxxxx_FLASH.ld    # Linker script
│
├── Sender/                         # (Bridge) ESP32-C6
│   └── ESP-IDF/
│       ├── main/
│       │   ├── CMakeLists.txt
│       │   ├── main.c              # UART -> ESP-NOW bridge + NVS + RMT
│       │   └── Kconfig.projbuild   # (optional)
│       ├── CMakeLists.txt
│       └── sdkconfig.defaults      # (optional)
│
├── Receiver/                       # (Receiver) ESP32
│   └── Arduino/
│       ├── src/
│       │   └── main.cpp            # ESP-NOW receive + Serial print
│       ├── include/                # (optional)
│       └── platformio.ini
│
└── README.md