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 Figure 1-2.

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 PinATmega3208 PinFunctionShared Functionality
RXPA0UART0 TX—
TXPA1UART0 RX—
RSTPD3GPIO—
P2_0 / MODEPF3GPIOSW0 and on-board debugger
P3_3 / RX_INDPD3GPIO—
P1_1 / STATUS1—BLE Connection LEDBLE LED
Info: The RST and MODE signals are pulled up by external resistors.