sending signal from AEP GW to mDot

[Micheal Le]

Hi,

Is it possible to program somehow the AEP gateway to send signal back to my mDot?

So, I currently have connection between mDot and the gateway. Gateway reads mDot’s rssi and etc and I am trying to send this rssi information that are received at gateway from mDot, then back to mDot

Is it possible to do so?

Thanks

• This topic was modified 7 years, 4 months ago by Micheal Le.

[Leon Lindenfelser]

Hi Micheal,

In Node RED on the Conduit AEP, you can add a function node between the LoRa input and output node with the following code.
msg.payload=msg.lsnr + msg.rssi;
return msg;

See this link.
https://www.multitech.net/developer/software/lora/conduit-aep-lora-communication/

Kind regards,
Leon

[Micheal Le]

Hi Leon,

Thank you for the information.

then how do I check the packet received on mDot?

Thanks

Regards,

[Leon Lindenfelser]

Hi Micheal,

Are you asking how to receive the packet or how to parse the data? If received, the packet will arrive in the first or second receive window… assuming you are using class A.

Kind regards,
Leon

[Micheal Le]

Hi Leon,

I am asking how to check whether messages has been sent back to the mDot or not from the gateway. When you mean by receive window, are you referring to the debugging window on nodeRed?

And also, how do we parse data thoes data?

Thank you!

• This reply was modified 7 years, 4 months ago by Micheal Le.
• This reply was modified 7 years, 4 months ago by Micheal Le.

[Leon Lindenfelser]

Hi Micheal,

The nature of LoRa communication is such that there is no guarantee that a down link or up link packet will be received on the other side. You can enable acknowledgements and link checks improve odds of delivery but at a cost. Reading the following link may help shed light on the matter.
http://www.multitech.net/developer/software/lora/introduction-to-lora/

The receive window I am talking about is the window that is used by the mDot to receive down link packets from the network server following an up link.

Kind regards,
Leon

[Micheal Le]

Hi Leon,

so when I put a function between lora input and output with following script,
msg.payload=msg.lsnr + msg.rssi;
return msg;

What would be the output node in order for a mDot to receive those data?

Thanks again

[Leon Lindenfelser]

Hi Micheal,

In the flow on this page
https://www.multitech.net/developer/software/lora/conduit-aep-lora-communication/
you see a LoRa input node and LoRa ouput node. The function node should be placed in between them.

Leon

[Micheal Le]

Hi Leon,

Yes I see them, but what do I need to choose for the output in order for my mDot to receive data? Sorry, I am quite novice to nodeRed.

Thanks

[Leon Lindenfelser]

Micheal,

I think you are expecting this to be more complicated than it is. In the Conduit node red screen, there is a list of input, output, function etc nodes in the left panel. From the input list, grab lora. From the function list, grab function. From the output list, grab lora. Connect as follows.
lora input———–function———-lora output
Double click the function node to insert code. Deploy it with the Deploy button in the upper right. Join the Conduit from the dot and do an AT+SEND=. See what you get back.

Leon

[Micheal Le]

Thank you Leon.

Is there anyway we can parse out those data that are received from gateway?? I am using mbed lib. to work with mDot.

I can see number of bytes are received, but not the actual value(rssi, lsnr)

Thank you again

[Leon Lindenfelser]

Hi Micheal,

With what I gave you, the data is probably ASCII formatted. I believe you can change the formatting of the data in the function node before sending it. Like set it to hex if that’s what you are looking for.

Leon

[Micheal Le]

Hi Leon,

I literally just see following view on serial monitor for mDot,
[INFO] successfully sent data to gateway
[INFO] Packet Received: 1 Bytes SeqNo: 10719

Is this something I have to work on mDot or on nodeRed?

Thanks

[Leon Lindenfelser]

Hi Micheal,

Assuming you are using our AT command code, the payload of the down link packet will be output on the main serial port… not the debug port.

I’m not sure if this might work for you but in our AT command code, the +PING command displays the RSSI and SNR that the gateway sees from the mDot in up link packets. The +RSSI and +SNR commands display the RSSI and SNR as seen in down link packets.

Leon

[Micheal Le]

Hi Leon,

I don’t have the serial connect so I cannot use AT commands at this moment.

As I mentioned above, I am currently using mbed libraries to work with mDot.

Is it possible to do with mbed libraries?

Michael

[Leon Lindenfelser]

Hi Micheal,

Assuming you are using class A mode, call recv() after send(). See the mDot.h api.

Leon

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