Alex's Corner - Week 3 - LoPy LoRaWAN Nano-Gateway & TTN

[palmy-nz]

Hi Alex, thanks for these videos.

I managed to get the nano-gateway working, using the Packet Forwarder protocol and finding out my Device EUI with these commands

import network
import binascii
binascii.hexlify(network.LoRa().mac())

However, I could not get the node working with the otaa_node.py example. I am getting this error:

ValueError: invalid argument(s) value

On this line

lora.add_channel(0, frequency=915100000, dr_min=0, dr_max=5)

Note I am on the 915 frequency (New Zealand). Has to be something to do with that aye?

Any advice appreciated.

Ps. I would love to see in an upcoming video how to pull data from sensors, and also push to nodes e.g. trigger led/servo.

[jmarcelino]

@palmy-nz
For the 915Mhz region the dr_max parameter (LoRa datarate setting) has to be 4 and not 5.

You'll also need to change the nano gateway script to match the frequencies and channel, please see this thread https://forum.pycom.io/topic/983/otaa_node-py-error/3

[bucknall]

Hi @palmy-nz please try the settings that @jmarcelino suggested and let me know how you get on. If this fails, I have another idea of what might have been the issue!

Data acquisition is definitely an interesting topic! I'll make sure it's on the list for Alex's Corner!

Cheers,

Alex

[palmy-nz]

Thanks @jmarcelino @bucknall

Changing the dr_max from 5 to 4 (for 915mhz) did fix this ValueError.

Now I am just getting Not joined yet

My gateway config.py looks like this

GATEWAY_ID = '70b3d54990c648be'

SERVER = 'router.au.thethings.network'
PORT = 1700

NTP = "pool.ntp.org"
NTP_PERIOD_S = 3600

WIFI_SSID = '***'
WIFI_PASS = '***'

LORA_FREQUENCY = 915100000
LORA_DR = "SF7BW125"   # DR_5

Anything glaringly obvious?

[bucknall]

@palmy-nz looks fine :) - have you set up an application on the TTN yet?

[palmy-nz]

@bucknall I do, but device status still 'never seen'.

My device eui, app eui, and app key all match node main.py (from otaa_node.py)

Not sure about the application handler, currently set to ttn-handler-us-west? no au (aussie) option

Where could I be looking?

[jmarcelino]

@palmy-nz
Did you change your nanogateway.py line 41 as in that thread I linked?

Where it says "freq": 868.1 should be "freq": 915.1

Then in your otaa_node.py remove all 3 lora.add_channel() lines and replace with

for channel in range(0, 72):
    lora.remove_channel(channel)

lora.add_channel(0, frequency=915100000, dr_min=0, dr_max=4)

This is necessary for 915Mhz regions

[palmy-nz]

@jmarcelino i had missed that change.

I have now changed the freq: and added the remove channel loop.

But still getting Not joined yet.

I tried changing s.setsockopt(socket.SOL_LORA, socket.SO_DR, 4) value, without any luck.

Here are my files...
Node - main py
NanoGateway nanogateway py
NanoGateway config py

[avinash]

@palmy-nz Did you get a chance to complete this?

I was able to connect my nano gateway to TTN, but te node is still getting "Not joined yet".
I'm using 868100000 frequency.

[jclo13]

@jmarcelino can you help me please?

I was able to connect my NanoGateway to TTN, then I connected a node and i no had problems, however, now I am having problems to connect the node, when I start the node the following messages appear in the NanoGateway:

[ 884.453] Received packet: {"rxpk": [{"data": "ABeYANB+1bNwQfHGnEnVs3BtML tNbMI=", "time": "2018-02-14T15:38:34.160580Z", "chan": 0, "tmst": 860755474, "s tat": 1, "modu": "LORA", "lsnr": 5.0, "rssi": -20, "rfch": 0, "codr": "4/5", "fr eq": 903.9001, "datr": "SF7BW125", "size": 23}]}
[ 884.710] Push ack
[ 887.718] Pull ack
[ 889.710] Pull rsp
[ 890.633] Sent downlink packet scheduled on 866.755, at 923.299 Mhz using SF12BW500: b' yZ\xe2\xb8 \x 191\xc3NL\xc7/\xba+\xf4\xc4'

but the node is still getting "not joined yet", I am using the 915 Mhz.