LoRa 2 click carries Microchip's RN2903 915 MHz Radio Modem compliant with regulations for use in the United States, Canada, Australia and New Zealand. The click is designed to use either a 3.3V or a 5V power supply. It communicates with the target microcontroller over a UART interface (TXD, RXD, CTS) with the addition of a Reset pin (RST) and RTS pin.
A European version is available separately.
NOTE: The antenna is sold separately.
RN2903 module
The RN2903 module has a specified range of >15km in rural and suburban settings, and >5km coverage in urban areas.
A LoRaWAN™ Class A protocol stack is embedded (bidirectional end devices), as well as an ASCII command interface accessible through UART. The high receiver sensitivity can go down to -146 dBm.
LoRaWAN™
LoRaWAN™ or Low Power Wide Area Network is a wireless technology developed to enable low data rate communications over long distances, mainly for IoT applications and sensors.
The architecture for this network is usually arranged in a star-of-stars topology. A gateway relays messages between end-devices (for example, battery operated devices in home automation) and a central core network server.
Key features
- RN2903 module from Microchip
- On-board LoRaWAN™ Class A protocol stack
- ASCII command interface over UART
- >15 km coverage at suburban areas
- >5 km coverage at urban area
- Low-Power Long Range Transceiver operating in the 915 MHz frequency band
- Onboard antenna connector
- UART interface
- 3.3V or 5V power supply
Pinout diagram
This table shows how the pinout on LoRa 2 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
| Notes |
Pin |
mikroBUStm
|
Pin |
Notes |
| Not connected |
NC |
1 |
AN |
PWM |
16 |
NC |
Not connected |
| Active-low device Reset input |
RESET |
2 |
RST |
INT |
15 |
CTS |
Communication UART CTS signal |
| Communication UART RTS signal |
RTS |
3 |
CS |
TX |
14 |
TXD |
UART transmit |
| Not connected |
NC |
4 |
SCK |
RX |
13 |
RXD |
UART receive |
| Not connected |
NC |
5 |
MISO |
SCL |
12 |
NC |
Not connected |
| Not connected |
NC |
6 |
MOSI |
SDA |
11 |
NC |
Not connected |
| Power supply |
+3.3V |
7 |
3.3V |
5V |
10 |
+5V |
Power supply |
| Ground |
GND |
8 |
GND |
GND |
9 |
GND |
Ground |
Programming
Code examples that demonstrate the usage of LoRa 2 click with MikroElektronika hardware, written for MikroE compilers are available on Libstock.
Code snippet
LoRa process must be kept inside an infinite loop.
1 lora_init( false, false, false, lora_cbk );
2 lora_cmd( "sys get ver", "", tmp_txt );
3 TFT_Set_Font( &Tahoma15x16_Bold, CL_BLUE, FO_HORIZONTAL );
4 TFT_Write_Text( tmp_txt, 50, 50 );
5
6 while( 1 )
7 {
8 lora_process();
9 }
Usage notes
Study the data sheet before applying either Lora or Lora 2 click in your designs.
For example, here's what the official data sheet states about compliance with USA regulations:
"The RN2903 module has received Federal Communications Commission (FCC) CFR47 Telecommunications, Part 15 Subpart C “Intentional Radiators†modular approval in accordance with Part 15.212 Modular Transmitter approval. Modular approval allows the end user to integrate the RN2903 module into a finished product without obtaining subsequent and separate FCC approvals for intentional radiation, provided no changes or modifications are made to the module circuitry."
On the other hand, in New Zealand, it would be your responsibility to prove the device is compliant. To quote from the data sheet: "RN2903 module RF transmitter test reports can be used in part to demonstrate compliance against the New Zealand "General User Radio License for Short Range Devices". New Zealand Radio communications (Radio Standards) Notice 2010 calls up the AS / NZS 4268:2008 industry standard. The RN2903 module test reports can be used as part of the product certification and compliance folder."
You can find all the relevant data on page 13 of the official data sheet.
