User Manual

RN4020 PICTAIL PLUS DAUGHTER BOARD
DS50002265A-page 2  2014 Microchip Technology Inc.
While in USB-to-UART Bridge mode, the board can be
plugged into a PC that supports serial COM ports.
When plugged in over USB mini-B receptacle J5 to a
PC, the board enumerates as a serial COM port. A ter
-
minal emulator application on the PC can be used to
open the COM port and issue commands when the
RN4020 is in Command mode, or to transfer data when
it is in Microchip Low Power Data Profile (MLDP) mode.
The USB-to-UART Bridge mode enables a simple com-
mand shell running on the USB-to-UART Bridge that is
used to control the GPIOs on RN4020 through the
PIC18. Typing $$$ with a carriage return on the termi
-
nal emulator will enter the PIC18 command shell, as
seen in Figure 2.
Typing $$$ with a carriage return a second time on the
terminal emulator will exit the PIC18 command shell.
There is a 1 second guard band duration for both entry
into and exit out of the command shell. Command shell
is entered or exited only if there is no data transfer
during the duration of the guard band.
FIGURE 2: PIC18 Command Shell
The supported commands are listed in Table 1. The
supported commands can be issued with carriage
return after entering the PIC18 command shell, as in
the example that is shown below.
OTHER INFORMATION
To obtain the most recent and complete RN4020 data
sheet, user’s guide, and code examples, visit the
Microchip web site: www.microchip.com/rn4020
REVISION HISTORY
Revision A (June 2014)
This is the initial release of this document.
EXAMPLE 1:
I#A,04 // Sets the PIC18 IO port RA2 to logic HIGH
I@C,02 // Sets the direction of PIC18 IO port RC1 to input
I%B // Reads the logic levels on PIC18 IO port RB
TABLE 1: BASIC COMMANDS SUPPORTED IN THE PIC18 COMMAND SHELL
Basic Commands Supported Description
I#X,YY Sets or Clears the IO port A/B/C on PIC18
I@X,YY Sets the direction of the IO port A/B/C on PIC18
I%X Reads the IO port A/B/C on PIC18
H Provides help on supported commands and may show additional
commands, if available
V Version of the command shell
Legend: X – A or B or C; YY – Hex byte value