WM1302 LoRaWAN Gateway Module

WM1302 module is a new generation of LoRaWAN gateway module with mini-PCIe form-factor. Based on the Semtech® SX1302 baseband LoRaWAN® chip, WM1302 unlocks the greater potential capacity of long-range wireless transmission for gateway products. It features higher sensitivity, less power consumption, and lower operating temperature than the previous SX1301 and SX1308 LoRa® chip.

WM1302 LoRaWAN gateway module has SPI and USB versions on both US915 and EU868 frequency bands, enable you to have a wide-range of LoRaWAN frequency plans options to choose including EU868, US915, AS923, AS920, AU915, KR920 and IN865.

WM1302 module is CE, FCC and Telec certified, which helps simplify the development and certification process of the LoRaWAN gateway devices.

WM1302 is designed for M2M and IoT applications and can be widely applied in LPWAN gateway supported scenarios. It would be a perfect choice for you to significantly reduce the technical difficulties and time-consumption when developing the LoRa gateway devices, including LoRaWAN gateway, miner hotspots, etc.

Getting Started

Difference between SPI version and USB version

For WM1302 LoRaWAN Gateway Module SPI version, the Semtech SX1302 and SX126x chip are conntected to Raspberry Pi via the same SPI bus with different chip select(CS) pin.

For WM1302 LoRaWAN Gateway Module USB version, the Semtech SX1302 and SX126x chip are conntected to a STM32L4 MCU, and this factory programmed MCU will work as a USB device, becoming a bridge between Raspberry Pi and SX1302/SX126x.

Quick Start with WM1302

Hardware Required

• WM1302 LoRaWAN Gateway Module

• Raspberry Pi boards with 40-pin GPIO header(e.g. Raspberry Pi 4B or Raspberry 3B+)

• WM1302 Pi Hat for Raspberry Pi

• Power Adapter for Raspberry Pi

• A LoRa antenna

• A 8G or larger SD card and a card reader

• A Type C USB cable if using WM1302 LoRaWAN Gateway Module USB version

Software Required

• Lastest Raspberry Pi OS image: Raspberry Pi OS Lite is recommended

• Balena Etcher: To flash Raspberry Pi OS image to SD card

• putty: To connect to Raspberry Pi via SSH on Windows

Step1. Mounting WM1302 Raspberry Pi Hat and install WM1302 module

It is easy to mount the Pi Hat on Raspberry Pi 40 Pin Header. Power off Raspberry Pi first, insert WM1302 module to the Pi Hat as the following picture and screw it down.

If USB version WM1302 module is using, please also connect its Type C port to the Raspberry Pi USB port with a Type C USB cable.

Step2. Enable the Raspbian I2C and SPI interface

WM1302 module communicates with Raspberry Pi with SPI and I2C. But these two interfaces are not enabled by default in Raspbian, so developer need to enable them before using WM1302. Here, we introduce a command line way to enable SPI and I2C interface.

First, login in Raspberry Pi via SSH or using a monitor(don't use serial console as the GPS module on the Pi Hat takes over the Pi's hardware UART pins), then type sudo raspi-config in command line to open Rasberry Pi Software Configuration Tool:

sudo raspi-config

1. Select Interface Options

2. Select SPI, then select Yes to enable it

3. Select I2C, then select Yes to enable it

4. Select Serial Port, then select No for "Would you like a login shell..." and select Yes for "Would you like the serial port hardware..."

5. After this, please reboot Raspberry Pi to make sure these settings work.

Step3. Get and compile SX1302 source code

Now let's install git and download sx1302_hal(library and programs for SX1302 LoRa Gateway) from github:

sudo apt update
sudo apt install -y git
cd ~
git clone https://github.com/Lora-net/sx1302_hal

Move to sx1302_hal folder and compile everything:

cd ~/sx1302_hal
make

Step4. Run Semtech SX1302 packet forwarder

Firstly, modify reset pin for SX1302 and SX1261 in reset_lgw.sh script, with text editor nano:

nano tools/reset_lgw.sh

The following code is shown at the head of text editor:

# GPIO mapping has to be adapted with HW
#

SX1302_RESET_PIN=23     # SX1302 reset
SX1302_POWER_EN_PIN=18  # SX1302 power enable
SX1261_RESET_PIN=22     # SX1261 reset (LBT / Spectral Scan)
AD5338R_RESET_PIN=13    # AD5338R reset (full-duplex CN490 reference design)

Use the navigation keys to move the cursor, change SX1302_RESET_PIN=23 to SX1302_RESET_PIN=17 and SX1261_RESET_PIN=22 to SX1261_RESET_PIN=5, as following:

# GPIO mapping has to be adapted with HW
#

SX1302_RESET_PIN=17     # SX1302 reset
SX1302_POWER_EN_PIN=18  # SX1302 power enable
SX1261_RESET_PIN=5      # SX1261 reset (LBT / Spectral Scan)
AD5338R_RESET_PIN=13    # AD5338R reset (full-duplex CN490 reference design)

Save these changes by pressing CTRL + x, and then y, finally pressing Enter to close the text editor.

Copy reset_lgw.sh to packet_forwarder folder, then run lora_pkt_fwd. Please note that you should select a global_conf.json.sx1250.xxxx config file based on the module you are using:

cp tools/reset_lgw.sh packet_forwarder/
cd packet_forwarder

# Please select one of the following comands based on your module
# for WM1302 LoRaWAN Gateway Module (SPI) - EU868
./lora_pkt_fwd -c global_conf.json.sx1250.EU868

# for WM1302 LoRaWAN Gateway Module (USB) - EU868
./lora_pkt_fwd -c global_conf.json.sx1250.EU868.USB

# for WM1302 LoRaWAN Gateway Module (SPI) - US915
./lora_pkt_fwd -c global_conf.json.sx1250.US915

# for WM1302 LoRaWAN Gateway Module (USB) - US915
./lora_pkt_fwd -c global_conf.json.sx1250.US915.USB

Now, packet forwarder are able to run correctly. But there are still something to do if developers need to forward lora packet to their LoRa Server(e.g. TTN or chripstack).

To achieve this target, developers must add the Raspberry Pi Gateway to Lora Server first. Take TTNv3 as an example, login TTNv3 console, click Go to gateways and click Add gateway, in the Add gateway page you will find dozens of settings to fill. What you need to focus on are Gateway EUI and Gateway Server address and Frequency plan, the others just leave it to the default.

• Gateway EUI: A 64 bit extended unique identifier for your gateway, we set it to AA555A0000000000 in this wiki

• Gateway Server address: The server addresss which gateway will connect to, copy this to clipboard, developers need to save this to the config file later

• Frequency plan: If using EU868 module, choose Europe 863-870 MHz (SF9 for RX2), if using US915 module, choose United States 902-928 MHz, FSB 2

After adding gateway, back to the Raspberry Pi, press CTRL + c to stop lora_pkt_fwd, then edit the global_conf.json.sx1250.xxxx config file you used just now, with text editor nano:

# Please select one of the following comands based on your module
# for WM1302 LoRaWAN Gateway Module (SPI) - EU868
nano global_conf.json.sx1250.EU868

# for WM1302 LoRaWAN Gateway Module (USB) - EU868
nano global_conf.json.sx1250.EU868.USB

# for WM1302 LoRaWAN Gateway Module (SPI) - US915
nano global_conf.json.sx1250.US915

# for WM1302 LoRaWAN Gateway Module (USB) - US915
nano global_conf.json.sx1250.US915.USB

Basically, you only need to modify these parameters: "server_address" "serv_port_up" "serv_port_down", which can be found at the tail of the config file. Copy Gateway Server address to "server_address", change "serv_port_up" and "serv_port_down" to 1700, these parameters should be edited like this:

"gateway_conf": {
    "gateway_ID": "AA555A0000000000",
    /* change with default server address/ports */
    "server_address": "eu1.cloud.thethings.network",
    "serv_port_up": 1700,
    "serv_port_down": 1700,

Save these changes by pressing CTRL + x, and then y, finally pressing Enter to close the text editor.

Restart lora_pkt_fwd, you will find your Raspberry Pi Gateway are conntected to TTNv3.

# Please select one of the following comands based on your module
# for WM1302 LoRaWAN Gateway Module (SPI) - EU868
./lora_pkt_fwd -c global_conf.json.sx1250.EU868

# for WM1302 LoRaWAN Gateway Module (USB) - EU868
./lora_pkt_fwd -c global_conf.json.sx1250.EU868.USB

# for WM1302 LoRaWAN Gateway Module (SPI) - US915
./lora_pkt_fwd -c global_conf.json.sx1250.US915

# for WM1302 LoRaWAN Gateway Module (USB) - US915
./lora_pkt_fwd -c global_conf.json.sx1250.US915.USB