Transparent UART service for BM70/RN4870
The Microchip Transparent UART Service available on the BM70/RN4870 BLE modules is used in this help guide to demonstrate an example using Android™ OS to connect with the BM70/RN4870 BLE modules. These modules support the Transparent UART Service and transfer data bi-directionally. This section provides the details of the Microchip Transparent UART Service and Characteristics UUIDs as well as access properties as they are used in the next section.
As a GATT Server, the BM70/RN4870 hosts the Microchip Transparent UART Service. The Transparent UART Service provides a simple bidirectional data transfer service. It defines two characteristics for data communication, one for receiving data with the Write property and the other for sending data with the Notify property. The Microchip Transparent UART Service is instantiated as a Primary Service on the BM70/RN4870 BLE module by default.
The UUIDs and access properties of the Microchip Transparent UART service and its characteristics are shown in the table below.
| Service Name | UUID | |
|---|---|---|
| Microchip Transparent UART | 49535343-FE7D-4AE5-8FA9-9FAFD205E455 |
| Characteristic Name | UUID | Properties |
|---|---|---|
| Microchip Transparent UART TX | 49535343-1E4D-4BD9-BA61-23C647249616 | Notify, Write, Write without response |
| Client Characteristic Descriptor | Read, Write | |
| Microchip Transparent UART RX | 49535343-8841-43F4-A8D4-ECBE34729BB3 | Write, Write without response |
Transparent TX Characteristic
This characteristic is used for data transmission by the Server or Client. Once the notification is enabled using the Client Characteristic Configuration Descriptor of Transparent TX by the Client, the Server sends data to the Client whenever it is updated by the Server. Optionally, the Client also can send data through this characteristic.
Transparent RX Characteristic
This characteristic is used for data transmission by the Client. The Client can send data to the Server by performing a Write operation on this characteristic.
The Microchip Transparent UART Service and its Characteristics are enumerated in the MCHP Transparent UART Android app example as shown in the screenshot below and will be used by the Android app as the GATT Client. Note the matching 128-bit UUIDs associated with the service and characteristics in the screenshot and the table above.
