SP0LND balloons − LoRa APRS Digi Info

Configuration ⚙️

The best way to configure your tracker is by using the SQ2CPA LoRa APRS flasher software, available at flasher.lora-aprs.pl.

You need to set the following frequencies and transmission parameters:

Transmission Settings
TX Frequency	`436.050 MHz`
TX Speed	`183bps` (SF12, CR4:8, BW125k)
RX Frequency (if you are normally using 1200bps)	`434.855 MHz` (1200bps)
RX Frequency (if you are normally using 300bps)	`433.775 MHz` (300bps)

Example software configuration:

Software configuration screen showing speed settings

Of course, here is the English version of the code snippet. You should paste it right after the section with the frequency table and before the section about how the digipeater path works. The best place is just before the

line that separates them. Code to Paste Copy the code block below. Remember to replace path/to/image1.png and path/to/image2.png with the correct filenames and paths for your images. HTML

Very Important: Ensure your tracker transmits frames only on the 436.050 MHz frequency. Do not send the same frame in parallel on other APRS frequencies (e.g., 434.855 MHz). The APRS-IS servers will detect a duplicate, and the frame repeated by the balloon will not be visible on the network!

Disable Telemetry 📡

It is strongly recommended to disable telemetry in your tracker. Sending additional telemetry data unnecessarily occupies valuable airtime on the channel and can interfere with the digipeater's operation for other users.

Below are examples of how to do this:

How the Digipeater Path Works 🛰️

Sending frames through the Digi balloon is based on a custom path system.

Important: The balloon's digipeater does not respect the standard WIDE path. You must use the SKY paths listed below.

Path	Description
`SKY1`	Your frame will be repeated by the balloon to the ground on 434.855 MHz (1200bps).
`SKY2`	Your frame will be repeated by the balloon to the ground on 433.775 MHz (300bps).
`SKY3`	This enables a balloon-to-balloon link. The first balloon repeats the frame to another balloon via 436.050 MHz.

To have a frame digipeated from one balloon to another and then to the ground, you must combine paths. For example, a path of SKY3,SKY1 will cause the first balloon to send your frame to the second balloon (via SKY3), which will then repeat it to the ground (via SKY1). A frame with only SKY3 will be ignored by the second balloon.

Recommended Mobile App

It is convenient to use the app.lora-aprs.pl web application. You can connect to your tracker via Bluetooth and set the desired path in the application settings. You can use this app for messages! Remember that path in application is related to messages and path in your tracker settings is related ONLY to tracker beacon!

Example app configuration:

Mobile app configuration screen showing path settings

Important Information ℹ️

Things to Remember

Airtime: A single frame's airtime is approximately 5 seconds. The channel capacity is very limited, so please do not spam frames!
Verification: After your frame is repeated, you can see the path it took on sites like aprs.fi.
GPS Spoofing: Be aware that GPS spoofing occurs in the Kaliningrad region. The balloon may temporarily report a false position or stop sending its location.
Message Acknowledgment: The balloon will respond with an acknowledgment (ack) to any message you send it. This confirms the balloon received your message.

Example of a successfully repeated frame on aprs.fi via two balloons: SN0PEK-14 and SN0PEK-15:

Screenshot from aprs.fi showing a repeated frame with a SKY path

Supported Commands 💬

You can send query messages to the balloon to get real-time information.

Command	Description
`?APRSV`	Returns information about the balloon.
`?APRSP` or `?APRSL`	Returns the balloon's current location (latitude and longitude).
`?APRSA`	Returns the balloon's altitude in meters.
`?APRST`	Returns the balloon's internal temperature in Celsius.