nvm_update

RNWF02 Firmware Update Utility

A Python utility for downloading firmware to RNWF02 devices using AT commands over serial communication.

What This Folder Contains

• nvm-update.py: main command-line tool
• requirements.txt: Python dependency list (pyserial)

Features

• AT command-based firmware download for RNWF02 devices
• Automatic NVM sector erase before update
• Chunked firmware transfer with configurable chunk size
• Real-time progress tracking with transfer speed
• Firmware verification and activation
• Device reset with firmware version check
• Verbose debug mode for troubleshooting
• Color-coded output for better readability
• Cross-platform support (Windows/Linux)

Requirements

• Python 3.6+
• pyserial library

Installation

1. Install dependencies:

pip install -r requirements.txt

How It Works

The firmware update process follows these steps:

1. Communication Check: Sends AT command to verify device is responding
2. Get Firmware Version: Retrieves current firmware version using AT+GMR
3. Erase Sectors: Executes AT+NVMER to erase NVM sectors (may take up to 30 seconds)
4. Download Firmware: Transfers firmware in chunks using AT+NVMWR=<offset>,<length>,<hex_data>
5. Verify Firmware: Validates the downloaded firmware with AT+OTAVFY
6. Activate Firmware: Executes AT+OTAACT to activate the downloaded firmware image
7. Reset Device (optional): Resets device with AT+RST and verifies new firmware version

Usage

Basic syntax:

python nvm-update.py -p <PORT> <FIRMWARE_FILE>

Parameters

• -p, --port: Serial port (e.g., COM3 on Windows, /dev/ttyUSB0 on Linux) - Required
  • To list available ports with details, run: python -m serial.tools.list_ports -v
• firmware: Path to firmware binary file (e.g., rnwf02_ota.bin) - Required
• -b, --baudrate: Baud rate for serial communication (default: 230400)
• -c, --chunk-size: Chunk size in bytes for firmware transfer (default: 128)
  • Note: Chunk size must be a factor of 4096 and ≤ 1024 bytes, since a write cannot cross a sector boundary
• -v, --verbose: Enable verbose debug output showing AT commands and responses
• --no-erase: Skip erasing NVM sectors before firmware download
• --no-activate: Skip firmware verification and activation after download
• --no-reset: Skip device reset after firmware update
• --read-verify: Perform a read verification after writing each chunk

Examples

Windows:

# Basic usage with default settings
python nvm-update.py -p COM5 rnwf02_ota.bin

# Custom baud rate
python nvm-update.py -p COM5 -b 921600 rnwf02_ota.bin

# Larger chunk size for faster transfer
python nvm-update.py -p COM5 -c 256 rnwf02_ota.bin

# Verbose mode for debugging
python nvm-update.py -p COM5 -v rnwf02_ota.bin

# Skip device reset after update
python nvm-update.py -p COM5 --no-reset rnwf02_ota.bin

# Skip sector erase (useful for partial updates)
python nvm-update.py -p COM5 --no-erase rnwf02_ota.bin

# Skip activation (download only)
python nvm-update.py -p COM5 --no-activate rnwf02_ota.bin

# Download only without activation or reset
python nvm-update.py -p COM5 --no-activate --no-reset rnwf02_ota.bin

Linux:

# Basic usage
python nvm-update.py -p /dev/ttyUSB0 rnwf02_ota.bin

# With custom settings
python nvm-update.py -p /dev/ttyUSB0 -b 921600 -c 256 rnwf02_ota.bin

Output Example

Starting firmware update...

Checking device communication...
✓ Device responding COM5 at 230400 bps

Getting firmware version...
✓ Firmware version: 3.2.0 1 74d4fbc2 [15:48:01 Jan 21 2026]

Erasing 240 sectors at offset 0...
✓ Sectors erased successfully

Downloading firmware from rnwf02_ota.bin (chunk size: 128 bytes)...
Chunk 1024/1024 (100%): 524288/524288 bytes
✓ Downloaded 524288 bytes in 45.2s (11.3 KB/s)

Verifying firmware...
✓ Firmware verified successfully

Activating firmware...
✓ Firmware activated successfully

Resetting device...
✓ Device reset command sent

Getting firmware version...
✓ Firmware version: 3.2.1 1 8a5c3fd9 [10:23:45 Jan 28 2026]

✓ Firmware update completed

AT Commands Reference

The utility uses the following AT commands from the RNWF02 specification:

• AT - Check device communication
• AT+GMR - Get firmware version information
• AT+NVMER=<offset>,<sectors> - Erase NVM sectors before firmware update
• AT+NVMRD=<offset>,<length> - Read data from NVM for verification
• AT+NVMWR=<offset>,<length>,<hex_data> - Write firmware chunk to NVM
• AT+OTAVFY - Verify downloaded firmware image
• AT+OTAACT - Activate the downloaded firmware image
• AT+RST - Reset the device

Troubleshooting

• Connection Failed: Verify COM port name and ensure device is connected
• Permission Denied: On Linux, you may need to add your user to the dialout group:

  sudo usermod -a -G dialout $USER

• Timeout Errors: Try using verbose mode (-v) to see detailed AT command exchanges
• Wrong Baud Rate: Verify device documentation for correct baud rate (default: 230400)
• Slow Transfer: Increase chunk size with -c 256 or higher
• Unexpected Response: Use verbose mode to debug AT command responses