[Jason Reiss]

Our current MTAC-LORA card has a USB interface.

Here is the gateway branch used for the gateway library in mLinux, it will show how to access the card
http://git.multitech.net/cgi-bin/cgit.cgi/lora_gateway.git/log/?h=1.7.0-mts

Otherwise the built in packet forwarder can be used accessed through UDP, lorawan is not required to receive and send packets through the radio.

Recipes for building the packet forwarder:
http://git.multitech.net/cgi-bin/cgit.cgi/meta-mlinux.git/tree/recipes-connectivity/lora

Documentation for communicating with packet forwarder:
https://github.com/Lora-net/packet_forwarder/blob/master/PROTOCOL.TXT

[Jason Reiss]

On the Conduit in lora-network-server version 1.0.8 and above the ADRStep setting will allow configuration of the sensitivity of the ADR algorithm. The default setting of 30 cB will allow 3dB per spreading factor setting determined by the received SNR of the last set of packets. The minimum setting is 25 cB (2.5 dB) which is the theoretical difference in link budget between each spreading factor.
Increasing the ADRStep above 30 will require a greater signal quality to reach the highest datarate.

The configuration setting should be:

"lora": {
...
    "ADRStep": 30 /* Step in cB between SNR based datarate assignment for ADR */
...

[Jason Reiss]

Is the lora-network-server process running?

> ps -A | grep lora

If not then check /var/config/lora/lora-network-server.conf is valid and there are not errors in /var/log/lora-network-server.log

Getting Started with LoRa Conduit mLinux (LoRa Configuration)

lora-query can also be used to provision nodes without using netcat, see downloads for latest version

LoRa Network Server

[Jason Reiss]

1. meta-mono could be installed on the AEP if the resources allow. With node-red and the lora network server also on the box the performance suffer. Installing an mLinux package on AEP will be lost in an upgrade. It would be better to use mLinux.

2. We do not provide C# libraries beyond what is included in meta-mono.

3. Loss of DeviceHQ and node-red, management for the cellular radio and router functionality that was in the GUI/API.

[Jason Reiss]

You may be able to maintain certification if you are able to compile with our prebuilt libmDot. We have a gcc archive available that may be able to be used with netmf.

Otherwise if you for go using our library, then you would need FCC/ETSI certification before commercialization.

The advantage of LoRa certification is customer confidence that the product has been tested against the protocol in an official manner.

[Jason Reiss]

The AT Firmware is the most complete example of using libmDot

The implementation of each Command in the default AT Firmware shipped on mDot is shown.

Also in CommandTerminal is the serialLoop function that reads from the serial port and send over the radio and vice versa.

https://developer.mbed.org/teams/MultiTech/code/mDot_AT_firmware/?platform=MTS-mDot-F411

[Jason Reiss]

To use the lora mcard you will also need a Conduit.

http://www.multitech.com/brands/multiconnect-conduit

It has two firmware options. AEP has a gui interface for device administration, Node-RED to manage data to and from the device, and access to our remote management platform, DeviceHQ. The mLinux model is for users interested in building their own linux image and integrating custom software.

More information can be found under the Software tab at the top of this page.

[Jason Reiss]

The output is changed in Node-RED. The “lora-in” node is where packets enter the flow.

You can either change the setting of the lora-in node to UTF-8 in Node-RED or create a function node that converts the payload from a buffer to a string.

msg.payload = msg.payload.toString("utf8");

return msg;

[Jason Reiss]

Max payloads for each datarate can be found here as well as SF and BW settings for each.

Introduction to LoRa

Coding rate will be 4/5 for LoRaWAN and programmed preamble is 8 symbols.

There is a “built-in preamble” of 4.25 symbols that the “Programmed preamble” excludes.

[Jason Reiss]

For US915 the minimum datarate is DR0 – SF10BW125

[Jason Reiss]

If you would like the content to be displayed, the lora-in node has the option to output a UTF-8 string instead of the buffer.

[Jason Reiss]

https://developer.mbed.org/teams/MultiTech/code/libmDot/wiki/libmDot-Change-Log

The new library has join backoff after a failed attempt. It is a time on air duty cycle backoff so it will depend on the datarate that was used for the join attempt.

A loop like this might work better.

while (!dot->getNetworkJoinStatus()) {
    osDelay(dot->getNextTxMs());
    if ((ret = dot->joinNetwork()) != mDot::MDOT_OK) {
        serial.printf("ERROR: failed to join network %d:%s\n\r", ret,  mDot::getReturnCodeString(ret).c_str());
    }
}

[Jason Reiss]

Q1) There is currently no support for multipart messages
a) Could you keep buffers in nodejs global context?

Q2) Use AT+SDR to get the current datarate used by the LoRaMAC layer

Q3) US915 Datarates
—————————
DR0 = SF10BW125 = 11 max bytes
DR1 = SF9BW125 = 53 max bytes
DR2 = SF8BW125 = 129 max bytes
DR3 = SF7BW125 = 242 max bytes
DR4 = SF8BW500 = 242 max bytes

[Jason Reiss]

It should be the AppEUI and AppKey settings from an already joined mote.
AppEUI – NetworkEUI
AppKey – NetworkKey

You can also get them from the network server process
> nc -u localhost 6677
config

These will be generated from Network Name and Passphrase on startup.
Otherwise these values could be provided in hex format if desired.

See “network” { “eui”: “”, “key”: “” }

[Jason Reiss]

Many of the fields are coming directly from the packet forwarder process.
Info can be found here:
https://github.com/Lora-net/packet_forwarder/blob/master/PROTOCOL.TXT

I will also add this info to our documentation for lora and node-red.

[Jason Reiss]

On the platform page is the list of pins and the mappings to the arduino pins used on the UDK2. You will have to program to the pin names in the center column.
https://developer.mbed.org/platforms/MTS-mDot-F411/

Each sensor on the weather shield should have examples already in mbed like this one:
https://developer.mbed.org/users/hwing91/notebook/htu21d—temperature-and-humidity-sensor/

[Jason Reiss]

Seems the cal_fw.var file and expected versions do not match.

The calibration firmware is loaded by the lora_gateway.

Either load the previous cal_fw.var from before Semtech release 2.0.0 or update the expected version to 3.

[Jason Reiss]

Are you compiling the Semtech version of 3.1.0 or TTN version?

TTN has commits past Semtech 3.1.0 to add Multitech support:
https://github.com/TheThingsNetwork/lora_gateway/commit/4f77b387f9893cb49749cf4d61ac4f9221829fc9

[Jason Reiss]

The things network is open source and has the latest releases of lora-net lora_gateway and packet forwarder with support for multitech hardware.
https://github.com/TheThingsNetwork/

We may update when we have an new version of MTAC-LORA gateway card.

[Jason Reiss]

See setTxDataRate() in mDot.h:
https://developer.mbed.org/teams/MultiTech/code/libmDot/file/121e4c454964/mDot.h

Also if ADR is enabled then the network server may change the datarate at the node. If this is not desired, which is the case with larger payloads then be sure ADR is not enabled.

[Jason Reiss]

The packet forwarder recipe and patches for mLinux are found here:
http://git.multitech.net/cgi-bin/cgit.cgi/meta-mlinux.git/tree/recipes-connectivity/lora

We are using the 1.4.1 version of the Semtech packet forwarder as a base.

[Jason Reiss]

This branch is built for mLinux:
http://git.multitech.net/cgi-bin/cgit.cgi/lora_gateway.git/log/?h=1.7.0-mts

It has the changes needed for MTAC-LORA support.

[Jason Reiss]

Select “complete message object” in the dropdown to see all properties.

Otherwise
msg.eui – will give the dev eui of the packet

[Jason Reiss]

The UDK2 MDOT build is powered through the USB only.

There is a plug-in at J3, but the voltage regulator is not populated.

[Jason Reiss]

Update your libmDot library to the latest and pass false as “deepsleep” to enter the STM411 STOP mode which will preserve RAM and continue execution by returning from the sleep call.

The older library only had support for the deepsleep/STANDBY mode in which all RAM is lost and execution start when programs is reloaded.

[Jason Reiss]

The CmdDummy entry is used to add the command into the help output because the implementation of the AT+SD command is built into the CommandTerminal.

The full implementation is found in the CommandTerminal.cpp file’s serial_loop function.

The multitech.net Downloads page has mDot 1.0.8 firmware with enhanced AT+SD functionality.

Try it out and see if it fits your needs.

[Jason Reiss]

To communicate over the DB9 connector use the XBEE_DOUT and XBEE_DIN pins.

The AT Command firmware is the application that provides the serial communication layer for libmDot.

There is an command in AT Command Firmware that reads data directly from the serial port and transmits the packets over LoRa. You may want to look at that as an example.

https://developer.mbed.org/teams/MultiTech/code/mDot_AT_firmware/

The serial code can be found in the serial_loop function.
https://developer.mbed.org/teams/MultiTech/code/mDot_AT_firmware/file/3c97f3048373/CommandTerminal/CommandTerminal.cpp

[Jason Reiss]

The 868 band has transmission limited with duty-cycles set in frequency bands. You must wait for a channel to be free after the required time-off-air after transmission according to the ETSI regulations EN 300 220-2 v2.4.1

[Jason Reiss]

Xiong,

I am not sure what info you are looking for. Can you clarify?

The mLinux instructions will also work with AEP. The LoRa network server is listening for MQTT or UDP messages for packets to forward to the mdot.

The lora-communication links for aep and mlinux in the previous posts are the proper methods.

Do you have a specific question about sending data that is not already covered by referenced documentation?

Thanks,

Jason

[Jason Reiss]

The DEV-EUI is available in the MQTT topic, lora/[EUI]/up.
The next version packets will have “mhdr” property that will include the NODE-ADDR in bytes 1-4.

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