#ham #radio #time #utility #sending

app minitransfer

A utility for sending and receiving files over ham radio. Uses the minipac protocol

2 unstable releases

0.2.1 Dec 20, 2022
0.1.0 Nov 7, 2021

#341 in Command line utilities

MIT license

186 lines


Minitransfer is a utility for transferring files over packet radio. It is based on the Minipac protocol. Because it uses Minipac, it has checksum validation and compression.

On a 2400 baud connection, I was able to send a 40 780 byte file in 2 minutes 19 seconds (from the time the program started, to the time it exited). Once compressed, 38 350 bytes of data was actually transferred. This represents an average speed of slightly over 2200 baud.


First, install cargo

Then, installing minitransfer is as easy as running `cargo install minitransfer'


Minitransfer requires a TNC to function. A TNC converts the digital stream of bytes into an audio signal. Although hardware TNCs exist, I use the software TNC Dire Wolf.

Sending a file

Run minitransfer URCALL-0 serve yourfile.jpg. URCALL-0 is your hostname, which is your callsign and a number between 0 and 255. You can also omit the number (and it will default to 0). This will default to 1200 baud to a KISS TNC on localhost:8001 (which is where Direwolf will listen by default).

This will set up a server. When a client connects over the air, it will automatically send the file.

Receiving a file

Run minitransfer URCALL-0 recv THEIRCL-0. As with the server, this will default to 1200 baud and localhost:8001.

This will connect to the server THEIRCL-0. Once it establishes a connection, it will print out the file name and the number of bytes that need to be transferred. The file will be downloaded, and it will exit once complete.

Pinging a server

Run minitransfer URCALL-0 ping THEIRCL-0. As with other commands, this will default to 1200 baud and localhost:8001.

The purpose of this command is to confirm that a connection can be established with the server. This is mainly meant to be used for debugging.


~226K SLoC