Info:
VBUS is powered from USB. Consequently, +5V will not be available while the board is powered
from a battery.
Info:
VCC_TARGET will have the battery voltage when the board is powered from a battery, which can
be less that +3.3V.
3.5.3
RN4870 BLE Module
The RN4870 is a Bluetooth
®
Low Energy (BLE) module that integrates a Bluetooth
®
5.0 baseband controller, on-
board Bluetooth stack, digital and analog I/O, and RF power amplifier into one solution.
Additional Features:
• Range up to 50m
• Operating Voltage Range: 1.9V to 3.6V
• TX / RX Mode Peak Current: 10 mA (typical)
• Low-Power Mode Current: 60 μA (typical)
• Shutdown Current: 2.9 μA (max)
The RN4870 BLE module is connected to the ATmega3208 through UART as well as three GPIOs for control and
configuring of the module. The RST signals resets the module, while the RX_IND signal is used to wake the module
from Low-Power mode. The MODE signal, available from the ATmega3208, the debugger as well as by a physical
switch, allows the module to be put in a “Test Mode” where the RN4870 firmware can be updated.
The module has one of its GPIO pins connected to an LED. By default, this will indicate connection status, but the
user can configure it for a number of other functions. Many of the other RN4870 GPIO pins are available as pads
around the label on the back side of the AVR-BLE board, as can be seen in
Info:
Some RN4870 settings have been changed during manufacturing of AVR-BLE. Using the
S-
command, the device name has been changed to “AVR-BLE”. In addition, the communication settings
have been configured for ATmega3208 UART0 settings of 9600,8,N,1.
Table 3-4. RN4870 Connections
RN4870 Pin
ATmega3208 Pin Function
Shared Functionality
RX
PA0
UART0 TX
—
TX
PA1
UART0 RX
—
RST
PD3
GPIO
—
P2_0 / MODE
PF3
GPIO
P3_3 / RX_IND
PD3
GPIO
—
P1_1 / STATUS1
—
BLE Connection LED
Info:
The RST and MODE signals are pulled up by external resistors.
Hardware User Guide
©
2020 Microchip Technology Inc.
User Guide
DS50002956A-page 17
