Hello,
I’ve been trying to connect my LoPy 4 to a Raspberry Pi running LoRa Gateway OS with a Sandbox shield.
I’ve gotten as far as seeing join request (uplink) and join accept (downlink) messages, but the LoPy 4 doesn’t seem to be acting on the downlink messages to initiate a connection.
The frequencies I’m seeing being used are 903000000 from the LoPy4 and 923300000 from the Raspberry Pi.
I have also followed some tutorials on setting up a ttn gateway using the same hardware and have been sucessful. I was wondering if anyone else has had success with a similar setup and can share if there were any necessary steps to get it working.
I have not specified any particular frequencies to be used by the LoPy 4 (and the same code was able to connect to the Raspberry Pi when it was configured as a ttn gateway).
Appreciate all the hard work.
Just an update, for anyone in a similar situation as I am. Edit your /etc/lora-packet-forwarder/global_conf.json to match that of https://github.com/TheThingsNetwork/gateway-conf/blob/master/US-global_conf.json except for the portion under “gateway_conf”. I also removed a lot of fields from the “gateway_conf” section leaving this:
"gateway_conf": {
"gateway_ID": "b827ebFFFE4bf67d",
"server_address": "localhost",
"serv_port_up": 1700,
"serv_port_down": 1700,
"keepalive_interval": 10,
"stat_interval": 30,
"push_timeout_ms": 100,
"forward_crc_valid": true,
"forward_crc_error": false,
"forward_crc_disabled": false,
"gps_tty_path": "/dev/ttyAMA0"
}
}
Good luck to anyone in the same situation, after this I was able to get a connection going from my LoPy4 to my Sandbox LoRaGo PORT.
No need to edit this yourself. In the latest LoRa Gateway OS version you can select the channel-block to use 
Thanks for this. I am still a bit confused as to why editing the global_config.json file vs. selecting channels 8-15 from the config script made a difference when trying to connect a lopy4. I’m wondering where the difference is (or how I managed to bungle this up).