Datasheet

RN4020
DS50002279B-page 4  2015 Microchip Technology Inc.
TABLE 1-1: PIN DESCRIPTION
Pin Name Description Function
1 GND Ground Ground
2 AIO2 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
3 AIO1 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
4 AIO0 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
5 UART TX UART Transmit (TX) Output
6 UART RX UART Receive (RX) Input
7 WAKE_SW
Deep Sleep Wake; active-high to wake module from
Deep Sleep. If the module runs without a host micro-
controller, connect the UART_RX pin to VDD via a
10K resistor to conserve power in Deep Sleep.
Input; weak pull down
8CMD/MLDP
Command or MLDP mode – In Command mode,
UART traffic is sent to the command interpreter. In
MLDP mode, UART traffic is routed to the MLDP
Bluetooth LED connection, if active.
Input; Edge triggered; Change
from High to Low to enter CMD
mode from MLDP mode
9 GND Ground Ground
10
CONNECTION
LED
PIO[1]
SCK
PWM1
Default state is output. Active-high indicates the
module is connected to a remote device. Active-low
indicates a disconnected state. Configurable as
PIO[1] via software command. SCK for Diagnostics
and Factory Calibration if pin 17 is asserted.
• Connection Status Indicator
(Green LED)
• PIO[1]
•SCK
•PWM1
11
MLDP_EV
PIO[2]
CS
PWM2
Default function is output used for MLDP data event
indicator (Red LED). Active-high indicates MLDP
data received or UART console data pending. Low
level indicates no events. Event is only triggered in
MLDP mode, when CMD/MLDP (pin 8) is high.
Configurable as PIO[2] via “|I” and “|O” commands.
CS for Diagnostics and Factory Calibration if pin 17
is asserted.
• MLDP Data Indicator (Red
LED)
• PIO[2]
•CS
•PWM2
12
WS
PIO[3]
MOSI
PWM3
Default function is an output used for Activity
Indicator (Blue LED). High level indicates module is
awake and active. Low level indicates module is in a
Sleep state. Accessible as PIO[3] via “|>” and “|<”
commands. MOSI for Diagnostics and Factory
Calibration if pin 17 is asserted.
• WS (Blue LED)
• PIO[3]
•MOSI
•PWM3
13
PIO[4]
MISO
MISO for Diagnostics and Factory Calibration if pin
17 asserted.
• PIO[4]
•MISO
14
CTS
PIO[5]
Reserved for CTS if hardware flow control is enabled
on the UART; active-low.
• CTS (input)
• PIO[5]