Additional information

The main system runs Debian GNU/Linux release Bullseye and we try to follow their guidelines.

Password Cheat Sheet

Description	User	Password
Web Interface	root	caduceu
WiFi Network	hermes	amazonia

Field trials

HERMES system prototypes were tested on a test bed with stations installed in three cities: Brasília/DF, Belo Horizonte/MG and Hortolândia/SP. Most of the tests happened between Brasília and Belo Horizonte, and Belo Horizonte and Hortolândia. The straight line distance between Brasília and Belo Horizonte is 620 km, while Belo Horizonte and Hortolândia straight line distance is 470 km. All the stations are equipped with simple dipole installed as inverted V, tuned to the 40m amateur radio band.

In our internal tests, between Belo Horizonte and Hortolândia, the modem reached more than 1000 bps in an average propagation condition (0db of SNR in the receiver). A 10Kb message, which is the typical size of an email with a picture takes about 4 minutes to be exchanged. In poor propagation conditions, this time can go up to 10 minutes.

The adaptive modem starts the communication with slower speeds, but if propagation is good, it gears up and automatically and increases the speed, and on the other hand, if propagation deteriorates, the modem reduces the speed, increasing the signal robustness.

Source Code

Source code is available inside the folders /home/hermen/install with the latest git versions before the deployment and is also available online at:

• Web Front-end Interface, written using the Angular framework: https://github.com/Rhizomatica/hermes-gui;
• Web Back-end Interface, written in PHP: https://github.com/Rhizomatica/hermes-api;
• HF transceiver description and schematics: https://github.com/DigitalHERMen/rhizo-transceiver;
• HF transceiver firmware and userland tools, written in C: https://github.com/Rhizomatica/hermes-net;
• UUCP-to-modem bridge (uucpd + uuport) for VARA-style TNC integration, written in C: https://github.com/Rhizomatica/hermes-net/tree/main/uucpd