In-Depth Analysis of the UWB650 Module (Part 3): Advanced Functions and System Maintenance

This chapter will explore the advanced features of the UWB650 module that go beyond basic communication and positioning. The content covers network scalability, hardware interface reuse, and the device's firmware lifecycle management, providing guidance for building more complex and powerful UWB application systems.

Extending Coverage with Mesh Networking

To address the issue of insufficient single-hop communication distance in large or complex environments with obstructions, the UWB650 module introduces a Mesh networking feature.

• Enabling the Feature: The Mesh feature is disabled by default and can be enabled using the UWBRFAT+MESHENABLE=command. This feature allows data packets to be relayed through multiple hops between nodes in the network, thereby greatly extending the effective coverage area of the network.

• Operating Modes: A module can play different roles in a Mesh network, specified by theparameter:

• type=1 (Pure Relay): The module acts only as a data forwarding node, neither generating nor consuming data. This is suitable for deployment in key locations to connect two separate network areas.

• type=2 (Pure Node): The module acts only as a source or destination node for data and does not participate in data forwarding.

• type=3 (Hybrid Mode): The module can act as both a data node and a relay. When it receives a data packet not addressed to itself, it will forward it. This is the most flexible mode, allowing any node in the network to participate in route construction.

• Key Limitation: To prevent data packets from circulating indefinitely in the network, which could cause broadcast storms and channel congestion, the firmware has a hard-coded limit of a maximum of 10 hops for forwarding. When a relay node receives a data packet that has already been forwarded 10 times, it will no longer forward it. Additionally, an important design constraint is that a module with the Mesh feature enabled cannot conduct regular data communication with a module that does not have it enabled (ranging and positioning functions are not affected). This means that once the decision is made to use Mesh, it is usually necessary to configure all communication nodes in the entire network uniformly.

Firmware Upgrade via YModem Protocol

The module supports firmware upgrades via the serial port, which provides the possibility for post-launch feature iteration and bug fixes, but it also places requirements on the hardware design.

• Entering Upgrade Mode: A firmware upgrade must be triggered under specific hardware conditions. The procedure is as follows: first, power off the module. Then, use an external circuit to pull pin 35 (UPGRADE) of the module to a low level (or short it directly to GND). Finally, power the module back on. At this point, the module will enter firmware upgrade mode and wait to receive the new firmware file via the serial port.

• Protocol and Tools: The firmware is transmitted using the standard YModem protocol, with a serial port baud rate of 115200 bps. Users need a PC-side serial port tool that supports the YModem protocol, such as ExtraPuTTY or the official SerialPortYmodem utility.

• Upgrade Process: The complete upgrade steps are as follows:

1. Perform the hardware operation to enter upgrade mode.

2. Connect the module's serial port to the PC and open a YModem-compatible serial tool, configuring the COM port and baud rate.

3.  After connecting, the serial terminal will display the YModem handshake signal sent by the module (usually a series of 'C' characters).

4.  In the PC tool, select the "Send File" function and choose the new firmware binary file to begin the transfer.

5.  Wait for the file transfer to complete.
6.  After a successful transfer, disconnect pin 35 from GND and then perform a complete power cycle of the module (power off and on).

7.  After restarting, the module will load and run the new firmware.

Here is an example using the official SerialPortYmodem tool:

1. Select the corresponding COM port and open it.

2. Browse and select the firmware file, then click Send to start the transfer.

3. Once the transfer is complete, a success message will pop up. At this point, disconnect pin 35 and restart the module.

• Hardware Design Consideration: The existence of the firmware upgrade mechanism means that if the product needs to support on-site or remote upgrades, the PCB design must consider in advance how to control the level of pin 35. A dedicated physical jumper, a reserved test point, or a GPIO from the host MCU can be used to control this pin. If this is overlooked during the design phase, subsequent firmware upgrades will become very difficult, potentially even requiring a physical recall of deployed devices.

In-Depth Analysis of the UWB650 Module Series

• In-Depth Analysis of the UWB650 Module (Part 1): Introduction to UWB Technology and the UWB650 Module

• In-Depth Analysis of the UWB650 Module (Part 2): Mastering Core Functions: Configuration and Usage

• In-Depth Analysis of the UWB650 Module (Part 3): Advanced Functions and System Maintenance

• In-Depth Analysis of the UWB650 Module (Part 4): Antenna Delay Calibration and Module Deployment Considerations & Best Practices

• In-Depth Analysis of the UWB650 Module (Part 5): Configuration Commands