iotgod/ipv6-over-lorawan

Based on Contiki-NG-4.4, LoRaMac-node, libschc, ChirpStack

(WIP) IPv6-over-LoRaWAN

• Based on Contiki-NG-4.4, LoRaMac-node, libschc, ChirpStack
• OTA via CoAP blockwise transfer
• DEMO video：https://www.bilibili.com/video/BV1ih411o7Uz

Introduction

• Now OTA via CoAP blockwise transfer is tested.

• Ping command between node to node, node to host, node to border router is tested.

• A hello world CoAP server on node is tested.

• Contiki-NG : works as layer 3 and above of IPv6 protocol stack for both node and server side, and can build applications easily on top of the stack.

• libschc : libschc is a C implementation of the Static Context Header Compression(see RFC8724), it is a header compression technique used in LPWAN. It works as the adaptation layer between IP and MAC layer, provide both the compression and the fragmentation mechanism. In the following tests, it is assumed that the MAC layer MTU is 51 byte.

• libschc NOTE: libschc is work in progress, it's internal state machine still has some bugs, for now only NO_ACK and ACK_ALWAYS fragmentation mode works and is tested. As an alternative, 6LoWPAN provided by contiki-ng can be used instead of libschc.

• LoRaMac-node : provide LoRaWAN node side MAC layer and the bottom layer driver used by contiki-ng such as RTC, UART...

• ChirpStack : works as LoRaWAN server on the host. ChirpStack provide MQTT integration whick can be used to send and receive device data.

• Architecture:

    node(contiki-ng)                              border router(contiki-ng)           Host(raspbian/ubuntu)
    +--------------+                                  +--------------+                   +---------+
    |App1 App2 App3|                                  |App1 App2 App3|                   | App1 ...|
    |              |                                  |              |   +-----------+   |         |
    |      UDP     |                                  |      UDP     |   |           |   |   UDP   |
    |     IPv6     |                                  |     IPv6     +---+ /dev/tun0 +---+  IPv6   |
    | 6LOWPAN/SCHC |                                  | 6LOWPAN/SCHC |   |           |   |         |
    |    LoRaMac   |                                  | libmosquitto |   +-----------+   +---------+
    +-------+------+                                  +---------+----+ 
            |                          ChirpStack               |
            |  +-------+     +-------+    +-----------+         |
            +~ |Gateway| === |Network| == |Application|..... APPserver MQTT integration ....
               +-------+     |server |    |server     |
                             +-------+    +-----------+
  

• OTA Memory Map:

          Internal Flash 
    +------------------------+
    |  OTA image downloaded  |
    +-------0x8038000--------+
    |    Current Firmware    |
    +-------0x8004000--------+
    |       bootloader       | 
    +-------0x8000000--------+  
  
          firmware binary
    +------------------------+
    |  Firmware Binary Code  |
    +-------0x0000200--------+
    |       blank fill       |
    +-------0x0000010--------+
    |        metadate        |
    +-------0x0000000--------+ 
     metadate:
     1. crc16 of Firmware Binary Code
     2. Size of firmware image
     3. uuid
     4. firmware version number    
  

howto

Hardware needed:

1. device node: Heltec Automation's LoRa Node 151
2. border router: raspberry pi 3B, Heltec Automation's HT-M01(lora gateway)

Step:

1. Follow instructions in Raspberry PI USB mode section in https://heltec-automation.readthedocs.io/zh_CN/latest/gateway/ht-m01/qucik_start.html#usb to setup lora gateway.

2. Login Raspberry, and follow instructions in https://www.chirpstack.io/guides/debian-ubuntu/ to setup chirpstack loraserver.

3. Follow instructions in https://www.chirpstack.io/guides/first-gateway-device/ to setup up LoRaWAN device configuration, for now we use a classC device.

4. Loraserver should ready to communicate with lora device node now

         git clone https://github.com/aenrbes/ipv6-over-LoRaWan.git
         cd examples/lorawan-border-router
         make
         sudo ./border-router -a 1 fd00::1/64
         (the "-a" option correspond the appID in chirpstack)
   

5. On your development computer

         git clone https://github.com/aenrbes/ipv6-over-LoRaWan.git
         (you need change Commissioning.h in arch/cpu/loramac/mac/Inc according to loraserver configuration)
         cd examples/hello-world
         make TARGET=loramac
   

6. Flash hello-world.hex into lora-node-151.

7. You can use ping command to ping each other now. Have fun!

OTA procedure

1. install libcoap-2 on host. refer to https://github.com/obgm/libcoap

2. start coap server on host, and put ota image on server, setup the firewall on host

         coap-server -d 1
         coap-client -m put -b 256 -f firmware-new.bin.ota coap://[::1]/ota
   

3. make flash image and flash into lora-node-151

         cd examples/lorawan-ota
         make bootloader
         make ota-image-example
         make flash
   

4. the OTA download procedure will start automaticlly, after a long time(about an hour, the download speed is really slow!!!) when the full ota image is downloaded, it will automaticlly reset the system, bootloader will replace current app image with the downloaded ota image, then jump to the new firmware. 5.in our example, the new firmware will simply printout "+ota-firmware-new+" via uart.

test picture

1. CoAP test, lora node work as CoAP server, use CoAP client in host (6lowpan).

2. Ping test, lora node B ping lora node A (schc).

3. Hardware platform.

4. other test picture is under test-picture/(include node ping host...)

note

If you want to use 6LoWPAN, you need to checkout to commit named "add downlink retry", the downlink retry does not work perfectly, it often miss ack from device node.

todo

Fix libschc further to support ACK_ON_ERROR fragmentation mode.

find out more:

• Contiki-NG: https://github.com/contiki-ng/contiki-ng
• LoRaMac-node: https://github.com/Lora-net/LoRaMac-node
• libschc: https://github.com/imec-idlab/libschc
• ChirpStack: https://www.chirpstack.io/

author's email

• [email protected], hctang