Key Features

• STM32L072CZT6 MCU for master control
• SX1276 Lora wireless chip
• LoraWAN Class A & Class C protocol
• Flexible rules to connect different RS485 devices 
• AT commands to change parameters

Description

IoT is becoming more and more popular these days, Lora as a significant member of IoT, has many applications in the smart city, smart building, and industry. For some terminal devices like Arduino and Raspberry Pi with sensors that transmit data var RS485 interface, now this RS485 to LoraWAN converter can help these devices to communicate by Lora.

The RS485 to LoraWAN converter is embedded by the SX1276 Lora chip. This converter can convert RS485 signals into Lora wireless signals and transmit them to the Lora gateway. For data uplink: RS485-LN sends user-defined commands to RS485 devices and get the return from the RS485 devices. RS485-LN will process these returns according to the user-define rule to get the final payload to upload to the LoraWAN server. For data downlink: RS485-LN runs in LoRaWAN Class C. When there downlink commands from the LoRaWAN server, RS485-LN will forward the commands from LoRaWAN server to RS485 devices.

For different regions, there are different frequency bands for Lora communication. Here provides four frequency bands which are US915MHz for the USA, EU868MHz for Europe, KR920MHz for Korea, and AU915MHz for Australia. 

Specification

Hardware System:

•  STM32L072CZT6 MCU
•  SX1276 Wireless Chip
•  Power Consumption (exclude RS485 device):
• Idle: 32mA@12v
• 20dB Transmit: 65mA@12v

Interface for Model:

• RS485 
• Power Input 7~ 24V DC.

Lora Spec:

• Frequency Range:
• Band 1 (HF): 862 ~ 1020 MHz
• Band 2 (LF): 410 ~ 528 MHz
• 168 dB maximum link budget.

• +20 dBm - 100 mW constant RF output vs.

• Programmable bit rate up to 300 kbps.
• High sensitivity: down to -148 dBm. 
• Bullet-proof front end: IIP3 = -12.5 dBm. 
• Excellent blocking immunity. 
• Low RX current of 10.3 mA, 200 nA register retention. 
• Fully integrated synthesizer with a resolution of 61 Hz. 
• +14 dBm high-efficiency PA.
• FSK, GFSK, MSK, GMSK, LoRaTM, and OOK modulation. 
• Built-in bit synchronizer for clock recovery. 
• Preamble detection. 
• 127 dB Dynamic Range RSSI. 
• Packet engine up to 256 bytes with CRC.
•  Automatic RF Sense and CAD with ultra-fast AFC. 

Part List

• 1 x RS485-LN
  
• 2 x DIN holders
  
• 1 x LoRa Antenna
  
• 1 x program cable