LR 3 Click

How does it work?

LR 3 Click as its foundation uses the 32001345, a low-power long-range RF technology-based transceiver module from Mipot. It offers a long-range spread spectrum communication with high interference immunity. The network is implemented as a star topology, where endpoints work in duty cycle mode, significantly reducing the overall power consumption. Coupled with the AES128 message encryption and low current consumption, LR 3 Click offers an easy and reliable solution for developing low-power, highly integrated IoT networks, security systems, alarm networks, and similar applications that require simple and reliable networking solutions.

This Click board™ can be configured to work as either END or MASTER NODE, by using simple AT commands. While working as the MASTER NODE, the Click board™ can use a set of master-specific commands, such as the pairing command. This command will add the end node which requested pairing, to the master network table. While working as the END NODE, LR 3 Click can issue slave specific commands/requests, such as the pairing request command, which will allow that end node to be paired with the master.

LR 3 Click communicates with MCU using the UART interface with commonly used UART RX and TX pins at data rates up to 115200bps for the data transfer. In addition to these features, the 32001345 also uses several GPIO pins connected to the mikroBUS™ socket. The WK pin routed on the CS pin of the mikroBUS™ represents the Wake-up function used for waking up the device, while the RST pin on the mikroBUS™ socket can perform Hardware Reset function by putting this pin in a logic low state. This Click board™ also has an indicator routed on the INT pin of the mikroBUS ™ socket, which will provide the user with feedback after a successfully received package and verified checksum.

LR 3 Click features the SMA antenna connector with an impedance of 50Ω, so it can be equipped with the appropriate 868MHz compliant antenna that Mikroe has in its offer.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. A proper logic voltage level conversion is performed by the TXB0106 voltage level shifter, while the LDO ensures that recommended values power the module. This allows for both 3.3V and 5V capable MCUs to use the UART communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on LR 3 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	INT	Data TX indication
Wake up	WKP	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power supply	+3.3V	7	3.3V	5V	10	+5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

LR 3 click electrical specifications

Software Support

We provide a library for the LR 3 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for LR 3 Click driver.

Key functions:

• void lr3_cfg_setup ( lr3_cfg_t *cfg ); – Config Object Initialization function.
• LR3_RETVAL lr3_init ( lr3_t *ctx, lr3_cfg_t *cfg ); – Initialization function.

Examples description

This example reads and processes data from LR 3 clicks.

The demo application is composed of two sections :

void application_task ( void )
{
#ifdef END_NODE
    strcpy( tmp_msg.payload, TEXT_TO_SEND );
   
    lr3_tx_msg.data_in = &tmp_msg.payload[ 0 ];
    lr3_tx_msg.n_bytes = strlen( TEXT_TO_SEND );
    lr3_tx_msg.destination_id = LR3_BROADCAST_MESSAGE;
    lr3_tx_msg.option = LR3_UNCONFIRMED_DATA_TX;
    if ( lr3_tx_message( &lr3, &lr3_tx_msg ) == 0 )
    {
        log_printf( &logger, "Message: "%s" sent to MASTER...rn", ( uint8_t * ) TEXT_TO_SEND );
        log_printf( &logger, "------------------------rn" );
    }
    
    Delay_ms( 3000 );
#endif
#ifdef MASTER
    lr3_read_message_process( &lr3 );
#endif 
} 

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.LR3

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.