Package contents BT578_V3 Serial Bluetooth adapter x1 DB9 male to female gender changer x1 USB to Type-C power/charging cable x1 User Guide (Electronic edition, click to download) Q1: What is the difference between the new BT578V3 and the old BT578? A1: BT578_V3 can directly replace the old BT578, but there are also some upgrades and changes. 1. BT578_V3 abandoned MiniUSB port and replaced it with USB Type-C power/charging port. 2. The power consumption of the new model is very low, the average power consumption is about 8 mA, while the average power consumption of the old model is 22 mA. 3. The communication distance of the new model is longer, the longest connection distance measured can reach 50 meters, and the old model is about 30 meters. 4. Some AT commands of BT578_V3 have been adjusted, and a carriage return and line feed should be added at the command end. Q2: I am trying to configure the adapter to change the BAUD rate. I downloaded your android app and successfully connected to the BT578_BLE on the app. However, when I send a AT command there is no reply. When I look at the adapter, the power light is on, the Bluetooth light is solid once I connect to the app. When I send a AT command the Serial Data Activity LED briefly flashes and then turns off. Could you please advise? A2: BT578_V3 does not support AT command via Bluetooth connection, you have to send AT command via RS232 physical connection. You must connect BT578_V3 to a serial port of your computer to send AT command. If your PC does not have a serial port, please buy a USB-RS232 cable to add a physical COM port to your computer. Our product, BT580, can support remote Bluetooth AT commands, please click here . Specification Standard: Bluetooth v3.0(SPP) and Bluetooth v4.2(BLE) Selectable Serial Baud Rate: 1200,2400,4800,9600,19200,38400,57600,115200 bps Serial Communication BLE Characteristic: 0000ffe1-0000-1000-8000-00805f9b34fb Typical Bluetooth Coverage: 30 meters (line of sight) TX Power: 5dBm RX Sensitivity: -95dBm Typical work ing Current: 8 mA Dimension and Weight: 78x34x16mm 3 0 g Bluetooth dual mode: Supports Classic Bluetooth Serial Port Profile(SPP) and new generation Bluetooth LE ( BLE ) . Could be connected to a computer or Android phone via SPP, or an Android or iOS phone via BLE. Lower power consumption than BT578_V2, but longer communication distance. Using the current popular Type-C interface for Power supply and charging. Can be connected to female or male serial port device by DB9 connector or converter. A green LED is used to indicate TX/RX activity of RS232 serial communication. Supports Pin 9 power supply, just connect pin9 to 4-6V and pin5 to GND. Built-in battery and charging circuit, more than 24 hours battery usage time. Supports AT command setting on computer to personalize name, baud rate, etc. Introduction BT578 Serial Bluetooth adapter is usually connected to a serial device by DB9 serial port, and then communicates with a mobile phone or a computer via Bluetooth SPP or BLE , and thus build a wireless link between the serial device and the computer or mobile phone. It can eliminate your conventional RS232 serial cables, connects communication both sides over the air, provides a wireless serial connection with more freedom and convenience.