The redditor is correct. Lora max is 256 bytes per packet. LoraWAN max is 222 bytes per packet.
https://www.sciencedirect.com/topics/computer-science/maximum-packet-size 4.2.1.6 Packet structure and time on air Fig. 4–4 shows the packet structure used by LoRa. LoRa offers a maximum packet size of 256 bytes. More details on the LoRa packet structure can be found in [5]. For the purpose of this chapter, the main part of interest is the preamble that is a sequence of constant upchirps, two downchirps, and a quarter of upchirp. https://arxiv.org/pdf/1607.08011 I am sad I missed this talk. I was dog tired last night. Patrick ---- On Fri, 04 Jul 2025 00:00:25 -0700 Russell Senior <russ...@pdxlinux.org> wrote --- > There were some questions at the talk that didn't get precise answers. > > From wikipedia (https://en.wikipedia.org/wiki/LoRa): > > "The LoRaWAN data rate ranges from 0.3 kbit/s to 50 kbit/s per channel." > > I haven't found anything yet that talks authoritatively about packet > size limits. A Reddit user suggested the maximum packet (payload?) size > was 255 bytes, but it's Reddit, so apply appropriate error bars. > > -- > Russell > > On 7/3/25 05:00, Russell Senior wrote: > > Tonight! > > > > On 6/25/25 00:25, Russell Senior wrote: > >> Who: Caleb Phillips > >> What: An Introduction to Meshtastic > >> Where: 1930 SW 4th Avenue, Portland, Oregon 97201-5304, Room 86-01 > >> When: Thursday, July 3, 2025 at 7 PM > >> Why: The pursuit of technology freedom > >> > >> Summary: > >> > >> Meshtastic is an open source mesh network application for low power > >> IoT devices. Rapidly reaching critical mass in Portland due to a fast > >> growing user community and low cost and accessible platform, it > >> provides an appealing playground for off grid and secure > >> communications experimentation and infrastructure design. This talk > >> will cover basics of the wireless tech, platform and hardware as well > >> as demo introductory usage with built nodes. > >> > >> Bio: > >> > >> Caleb Phillips is featherless biped who is passionate about public > >> domain software and science. His day job is at a government > >> laboratory working on renewable energy technology and he comes from a > >> background in academic wireless systems research, data science, > >> statistical modeling and visualization. Locally he has done work with > >> the Personal Telco Project and other organizations. His website is > >> http://smallwhitecube.com. > >> > >> > >> PLUG is back at Portland State University. Thanks to the Computer > >> Science Department and to Andrew Greenberg for hosting us! The room > >> is in the basement of the PSU Engineering Building (also connected > >> underground to the Fourth Avenue Building, or FAB). Enter through the > >> Engineering Building. The outside door will be locked, but there > >> should be someone present at the entrance to let you in starting at > >> 6:40pm until 7pm. There will be a sign on the door with a phone > >> number you can SMS if there isn't someone there to let you in > >> immediately. > >> > >> https://calagator.org/events/1250482087 > >> > >> With luck, the talk will also be streamed live here: > >> http://www.twitch.tv/kngbwlf, and later posted to YouTube. > >> > > > >