User's Manual

RN4020
DSXXXXXXXXA-page 6  2014 Microchip Technology Inc.
3.0 MICROCONTROLLER TO RN4020 INTERFACE
FIGURE 3-1: INTERFACE DESCRIPTION
Figure 3-1 illustrates the interface between PIC micro-
controller and RN4020 module. The minimum interface
consists of UART and WAKE HW line. This enables the
microcontroller to communi cate with RN 4020 module
using ASCII comman d API. T he command API is
described in Sec XX.
3.1 CTS/RTS Hardware Flow Control
For customer applications using the Microch ip Low
Energy Data Protocol (MLEDP), Pin 8 (CMD/DATA) is
required. CTS/RTS hardware control is also highly rec-
ommended for this service to avoid buffer overruns.
3.2 Microchip Low Energy Data
Protocol (MLDP)
The Microchip Low En ergy Data Protocol i s a private
BTLE service that provides a 20kbps serial data trans-
port over Bluetooth Low Energy on the RN4020. Pin 8
(CMD/DATA) is required. CTS/RTS hardware control is
also highly recommended for this service to avoid data
loss.
Refer to “ RN4020 Command Reference”, for more
information on how to configure the MLDP service
mandatory for DFU over UART.
DRAFT