power_<n>=<power>. This is the power setting used for uplinks. Refer to the LoRa manual for details on setting this. ** Only set values that are legal in your location (for EU see IR2030) **
UplinkTime_0=<seconds>. When to send any uplink messages, measured as seconds into each cycle.
UplinkCycle_0=<seconds>. Cycle time for uplinks. First cycle starts at 00:00:00. So for uplink time=2 and cycle=30, any transmissions will start at 2 and 32 seconds after each minute.
If the frequency_n line is commented out, then that channel is disabled.
Uplinks
=======
The gateway can uplink messages to the tracker. Currently this is restricted to time-based uplink slots using "UplinkTime" and "UplinkCycle".
The code uses Linux system time, so the gateway should ideally be using a GPS receiver the GPSD daemon. NTP may prove sufficient however.
For uplinks to work, both UplinkTime and UplinkCycle have to be set for the appropriate channel.
There are currently two types of uplink supported:
- Uplink of messages from the "SMSFolder" folder. For this to work, "SMSFolder" has to be defined and present. The gateway will then check for "*.sms" files in that folder.
- Uplink of SSD packet re-send requests. The gateway looks for an "uplink.txt" file in the gateway folder. The file is created by an external Python script (supplied) which interrogates the SSDV server.
Calling Mode
============
It is possible for trackers to send out messages on a special "calling channel" as well as telemetry on their main frequency. The calling channel messages state the main frequency and LoRa modes.
This allows for gateways tp be normally left on the calling channel, so they then switch to each tracker as it comes within range.
There's nothing special about "calling mode" except that after a period (CallingTimeout seconds) of time without packets, the gateway returns to its default settings.
The display has a title bar at the top, scrolling log at the bottom, and 2 channel panels in the middle. Each panel shows something like:
Channel 0 869.8500MHz
Explicit, 250k, SF7, EC4:6
Telemetry 74 bytes
51.95028, -2.54443, 00138
Habitat SSDV 0000
0s since last packet
Telem Packets = 37
Image Packets = 0
Bad CRC = 0 Bad Type = 0
Packet SNR = 10, RSSI = -67
Freq. Error = 1.0kHz
Current RSSI = -64
The "Habitat" text appears during uploads to habitat. Normally it will flash up then disappear quickly; if it stays on (not flickering) then the upload is slow.
The "SSDV 0000" text shows the current state of the SSDV upload buffers. There are 4 upload threads and each can handle up to 16 (0-9-A-F) packets in its queue.
Normally, even with fast SSDV, uplinks should happen quickly enough for there to be no more than 1 or 2 active threads each with 1 packet being uploaded.