Microchip Technology RN4870 User Manual

RN4870/71 Bluetooth
®
Low Energy Module User’s Guide
DS50002466A-page 60  2016 Microchip Technology Inc.
As shown in Figure A-1, the GATT Client can access the characteristics in the GATT
Server in the peripheral device. When connected, the client reads the GATT Server ser-
vice and characteristic UUIDs. The characteristic values can be accessed by the GATT
client using Write, Read, Indication and Notifications.
Write-REQ enables client to update characteristic values on the Peripheral's GATT
server. The write requests can be performed using RN4870 CHW and CUW commands.
For more details on GATT characteristic access commands, refer to
Section 2.9 “Characteristic Access Commands”.
A Write-CMD message performs an unacknowledged write from a client to the server.
This is enabled for UART Transparent writes on the RN4870 when SR,0100 command
is used.
A client sends Read-REQ to read a characteristic value on the Peripheral's GATT
server. The write requests can be performed using RN4870 CHR and CUR commands.
Notifications and Indications are unsolicited updates sent from the Server to the Client.
The client must enable the notification and indication on a characteristic to receive the
updates. On the RN870 module, this done by using the CUW or CHW command to write
non-zero value to the Notification Characteristic. When RN4870 in client mode receives
a notification, the %WC,hhhh,ddddddd% message is returned on UART in Command
mode.
FIGURE A-1: GATT SERVICE IN RN4870
RN4870
[GAP Peripheral, GATT Server]
GATT Server Service
Public Service 16-bit UUID
Characteristic 16-bit UUID
Properties & Descriptors
Characteristic 16-bit UUID
Pro
p
erties & Descri
p
tors
Characteristic 16-bit UUID
Pro
p
erties & Descri
p
tors
Private Service 128-bit UUID
Characteristic 128-bit UUID
Properties & Descriptors
Characteristic 16-bit UUID
Pro
p
erties & Descri
p
tors
Characteristic 128-bit UUID
Pro
p
erties & Descri
p
tors
BTLE Device
[GAP Central, GATT Client]
Central-Client devices
include the following:
x SmartPhone
x Host PC
x Tablet
x RN4020 module
x RN4870 module
x Other BTLE device
GATT Client Write-5(4
GATT Client Read-5(4
GATT Notification
GATT Indication
ACK-Write-REQ
Read-RESP
GATT Client Write-&0'
ACK-Indication

Microchip Technology RN4870 Specifications

General

Brand	Microchip Technology
Model	RN4870
Category	Motherboard
Language	English