{"id":1041,"date":"2026-07-04T17:16:41","date_gmt":"2026-07-05T01:16:41","guid":{"rendered":"https:\/\/salemdata.net\/johnpress\/?p=1041"},"modified":"2026-07-04T17:16:41","modified_gmt":"2026-07-05T01:16:41","slug":"reticulum-a-precision-trace-among-7-nodes","status":"publish","type":"post","link":"https:\/\/salemdata.net\/johnpress\/?p=1041","title":{"rendered":"Reticulum: A Precision Trace Among 7 Nodes"},"content":{"rendered":"

What actually happens inside a Reticulum mesh running over LoRa when two endpoints cannot communicate directly?<\/p>\n

I built a seven-node testbed using LilyGo T-Beam SUPREME units named AMY, BOB, CY, DAN, ED, FLO, and GUY. AMY and GUY exchange one encrypted \u201cHi\u201d message per minute, while software-defined radio blocks force their traffic through the other five nodes as transports.<\/p>\n

All seven units discipline their clocks from GNSS satellites. In a roughly 17.5-minute synchronization run, the span among their median end-to-end observed clock offsets was about 0.166 ms, or 166 microseconds, and the minute-by-minute spread remained below about 0.633 ms. That common time base makes it possible to correlate events across seven independent logs with useful precision.<\/p>\n

Background<\/h2>\n

I have seven LilyGo T-Beam SUPREME units named AMY, BOB, CY, DAN, ED, FLO & GUY.\u00a0 The T-Beam is a small electrical assembly of components including a very powerful ESP32-S microprocessor which features wifi, bluetooth. There are also modules GPS<\/span>1<\/sup><\/a><\/span> and LoRa radio.\u00a0 Reticulum\u2019s reference implementation is written in Python. For these constrained ESP32-based devices, I chose Chad Attermann\u2019s C++ microReticulum implementation. <\/span>2<\/sup><\/a><\/span><\/p>\n

\"Firefighters
Los Angeles County Firefighers Demonstrating A Bucket Brigade (2019)<\/figcaption><\/figure>\n

The T-Beams running microReticulum can provide a mesh network which essentially means some units can act as forwarders or middlemen between two radio units that are out of range from each other. I like to analogize a mesh network as akin to a bucket brigade.<\/p>\n

 <\/p>\n

What I have Accomplished as of July 4, 2026<\/h2>\n

I have modified microreticulum by riddling it with debug statements so I can understand what is going on at every step.\u00a0 Since my 7 units are all in proximity to one another, I have used blocks written into the software to simulate a field test where all units are dispersed and no more than two units are within range of each other.<\/p>\n

\"\"
Seven Nodes<\/figcaption><\/figure>\n

Here is a diagram of the 7 units showing the possible paths of radio communication when they are all in the same room.\u00a0 What I have done is create artificial “blocks” in the software among various pairs so that Reticulum packets between AMY and GUY are forced to go through the other five units which act as transports.\u00a0 Since each unit has a custom block list, each unit has to be individually compiled.\u00a0 During my development I found that I could compile a 7 different firmwares on my high end server and save turn-around time by doing in 2 minutes what would take 10 minutes.<\/p>\n

A major hurdle I had to overcome was disciplining the clocks on each unit so everyone had the same time.\u00a0 That way when they produce logs, all the logs are using the same time and small differences such as one thousandth of a second, or more, can be accepted as real and not an aberration of different clocks.\u00a0 Learning to synchronize time to satellites took several weeks, and yesterday, to my surprise, I found Internet celebrity Engineer Jeff Geerling wrestling with the same issue with his pal Sean Hodgins<\/a> in their collaboration and whimsical: The Most Accurate Watch That Doesn’t Tell Time<\/a>\u00a0 \u00a0In a roughly 17.5-minute run, the span among the seven units\u2019 median end-to-end observed clock offsets was about 0.166 ms (166 \u00b5s — yes, that is 166 millionths<\/strong> of a second), with the minute-by-minute spread remaining below about 0.633 ms.\u00a0 The clock-synchronization analysis covered roughly 17.5 minutes. The detailed chronology and CAD plots below are from a separate 10-minute message run.<\/p>\n

My test run consists of the following:<\/p>\n