BLE2 click

Description of product

BLE2 click is an excellent choice if you want simple, temporary connectivity with your smart devices over Bluetooth 4.1.

BLE2 click features the RN4020 module from Microchip, that integrates RF, a baseband controller, and a command API processor, making it a complete Bluetooth Low Energy solution. The click communicates with the target board MCU through mikroBUS™ RX, TX and AN (CMD), PWM (con.), and RST (wake) lines. The board is designed to use 3.3V power supply only.

Microchip Low-energy Data Profile

The RN4020 has Microchip’s Low-energy Data Profile (MLDP) which enables an asynchronous serial data connection between two RN4020 devices (which could be two BLE2 clicks). The module can be remotely controlled or updated over-the-air by another module over a secure connection or can be controlled or updated through its UART interface.

PCB trace antenna

The RN4020 module aboard BLE2 click incorporates a PCB antenna with a range of at least 30m

Bluetooth 4.1

Bluetooth 4.1 is intended for IoT, it has low power consumption and lets any device be a peripheral and a hub at the same time.


Type Bluetooth,BLE
Applications Bluetooth Low Energy is becoming a pervasive standard for IoT applications in any number of domains (home automation, fitness, health and so on). Because of MLDP support, BLE2 click works great in pairs
On-board modules MicroChip RN4020
Key Features N4020 Bluetooth 4.1 module. PCB antenna. Integrated TCP/IP stack
Key Benefits MLDP support makes it easy to connect a pair of BLE2 clicks. Can be setup both as a client or a server
Interface UART,GPIO
Input Voltage 3.3V
Compatibility mikroBUS
Click board size  S (28.6 x 25.4 mm)

Pinout diagram

This table shows how the pinout on BLE2 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes Pin Mikrobus logo.png Pin Notes
Indicates connection state CONN 1   AN      PWM   16   CMD/MLDP       Command or MLDP mode  
Deep Sleep Wake SWAKE 2 RST INT 15 NC
NC 3 CS TX 14 BT_UART_TX UART Transmit
Power supply +3.3V 7 3.3V 5V 10 NC
Ground GND 8 GND GND 9 GND Ground


The code sets up the BLE2 click board, and sends messages through Bluetooth low energy every 5 seconds. If the BLE2 click board receives messages over Bluetooth low energy, the code displays the message and updates the buffer.

01 void main() {
02   Display_Init();
03   MCU_Init();
04   #ifdef INIT_BLE
05   BLE_Init();
06   delay_ms(2000);
07   #else
08   RN_WAKE = 1;
09   wait_response("CMD");
10   #endif
11   DrawFrame();
12   InitTimer2();
13   while(1)
14   {
15     if(data_ready)
16     {
17       //If characteristic is configured as write
18       //received messages come here
19       Display_Message();
20       reset_buff();
21     }
22     else
23     {
24        //Test: every 5sec increase baterry level (0 to 100%)
25        //and send value via Bluetooth Low Energy
26        if (tmr_flg)
27        {
28           batt_level++;
29           if(batt_level > 100)
30           {
31             batt_level = 0;
32           }
33           Display_BatteryLevel();
34           if(RN_CONN)
35           { //send battery level value if BLE connected
36             shorttohex(batt_level, batt_level_txt);
37             ltrim(batt_level_txt);
38             ble2_write_server_characteristic_value_via_UUID("2A19",batt_level_txt);
39           }
40           tmr_flg = 0;
41        }
42     }
43   }
44 }