Qianli iBridge A3 PC Monitor

A reverse-engineered Python client, graphical desktop application, and web-based visualization tool for the Qianli iBridge A3 USB Tester (Tail-YCS).

Overview

The Qianli iBridge A3 lacks native PC connectivity out of the box. This project reverse-engineers the serial protocol over USB to enable real-time tracking, logging, and visualization of voltage and current data.

1. Web Monitor (WebUSB)

The quickest way to get started. A lightweight, zero-installation web interface available directly in the browser via WebUSB.

Launch the Web Monitor

Note: Requires a WebUSB-compatible browser such as Google Chrome, Microsoft Edge, or Opera.

2. Desktop Visual Monitor

A Python-based desktop application providing a digital multimeter-style GUI and a scrolling history graph.

3. Python API

A simple, reusable QianliClient class that allows developers to integrate real-time readings into their own automation or testing scripts.

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Installation (Desktop & API)

1. Ensure Python 3.x is installed.
2. Install the required dependencies:

   pip install pyserial tk

Usage

Desktop GUI

Launch the visual monitor by passing your device's COM port as an argument:

python visual_monitor.py COMx

(Replace COMx with your specific serial port, e.g., COM5 on Windows or /dev/ttyUSB0 on Linux).

Python Implementation

To use the underlying library directly within your own scripts:

from QianliClient import QianliClient

client = QianliClient("COM5")
if client.connect():
    client.enable_stream()
    voltage, current, time = client.get_latest_reading()
    print(f"Voltage: {voltage} V, Current: {current} A")

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Protocol Documentation

The reverse-engineered protocol specifications for the serial communication.

Connection Parameters: USB Serial, 115200 baud, 8N1.

Packet Structure

The protocol uses a fixed-header, variable-length packet format.

Offset	Field	Type	Size	Description
0	Magic	uint8	1	Constant 0xDA
1	Length	uint16_le	2	Size of the Payload buffer (Little Endian)
3	Model	uint8	1	Device Mode / Target (e.g., 0x04)
4	Command	uint8	1	Command ID (e.g., 0x05)
5	Param 1	uint8	1	Parameter 1 (Usually 0x00)
6	Param 2	uint8	1	Parameter 2 (Usually 0x00)
7	Checksum	uint8	1	XOR of all Payload bytes (0 if Len=0)
8	Payload	bytes	Len	Variable length data

Control Commands

• Enable Data Stream: Model 04 Cmd 05 Payload 00
• Disable Data Stream: Model 04 Cmd 05 Payload 01

Data Stream Payload Format

When enabled, the device responds to Model 04 Cmd 05 with an 8-byte payload.

Offset	Field	Type	Size	Scaling Factor
0	Current	uint32_be	4	Value / 10000.0 = Amperes
4	Voltage	uint32_be	4	Value / 1000.0 = Volts

Note: All data values in the payload are Big Endian.