Pymesh updates

  • Hi community 🙌

    I want to share with you the Pymesh (LoRa Mesh) current development and plans; last release of Pymesh is in v1.20.0.rc7
    For starting, this is my Pymesh presentation(workshop) done at TTN Conf Jan 2019 Amsterdam; if you have any questions 🗣
    As I've said in a previous mail, currently I'm working on the Border Router feature, I try to explain in a nice micropy script, basically how Pymesh data can be exposed outside of mesh, on Wifi/BLE/Cellular to the ☁.
    Not to forget the 📕 were copied here: and with a disclaimer, as Pymesh is included just in RC (development) releases.
    But, no worries, 😅 we'll include it in the first official stable.
    We're planning in releasing firmware releases with and without Pymesh, due to relatively large (~200KB) code-size.
    I'm working at the road-plan for further Pymesh features.
    Long-term plan is exposing more openthread features, make tons of tests (lots of nodes, distance); connect Pymesh with Pybytes, optimise power-consumption, security for private Pymesh, profile some KPI (data able to be sent over Pymesh), and of course share all plans with community (basically I will open-source the micropy scripts presented in workshop, have some articles to explain all use-cases).
    Just let me know your thoughts, about the further projects, and we could include requirements into official development.

  • Just seen there is some new firmware for FiPy and Lopy4, are you going to create a version for use on L01 modules?



  • hi @eranroll
    Yes, indeed before I've frozen, just for demo purpose.
    Now (just now, I've updated binaries), the Pymesh is a frozen library, and using a nice you can play with Pymesh features.

  • @catalin Thanks for the reply! I was able to load the tar files you had uploaded using the PyCom Firmware Updater.
    However, I am not sure I follow its purpose. LoRa Mesh communication will start working on boot? From that point forward messaging over the LoRa Mesh network is done only using the Mesh CLI?

    I am able to run a file of lib/pymesh for example, but only after a few CTRL+C which stop the MESH THREAD.

  • @robert-hh That is providing Pycom build the firmware for the LoPy and include the LoRa Mesh functionality.


  • @thinginnovations You should expect that the LoPy4 firmware will only work on the L04 module (SX1276 chip) and the LoPy1 firmware will work on the L01 module, making however use of the larger RAM and flash. Similar to the WiPy firmware which works on both WiPy2 and WiPy3.

  • For Lopy4 release, will this work on the L01 modules as this has the same flash and ram as the Lopy4 or will it be only limited to the L04 OEM modules?



  • @catalin wouldn't it possible to put that closed stuff in a binary lib which will be linked when one builds the firmware?

  • @catalin Thanks for the reply!

    Open-source would be nice!

    Looking forward to the upcoming release!



  • @Danne @eranroll
    For the moment we have removed the open-source Pymesh components from the public repositories, and also from the binary releases.
    We prepared a process to release binary Pymesh releases, but the licensing is not yet set.
    Honestly, we're not sure if we'll release open-source, depends on the licensing process.

    I intend next week to release here binaries for Lopy4 and Fipy, which would work with scripts from here.

  • First of all, let me thank you for this excellent project!
    Pymesh paves way for many very interesting projects!

    I have started on a project using a pymesh network, it's a simple network with LoPy4 nodes and WiFi access points with web-servers allowing people to find each other and then send encrypted messages over the Loramesh. I want to add batteries and solar-cells to the mesh nodes to make this project completely off-grid.

    Cellphone  <- HTTP over WiFi -> LoPy4 <-> LoRa Mesh

    Questions for @catalin:

    • Which firmware would you recommend for the early development of products using mesh? Should I wait for the upcoming release?
    • I would like a version of the firmware with source-code to be able to debug things like "InstrFetchProhibited". The latest version of the Firmware ( does not include the OpenThread in pycom-esp-idf . Is there a developer branch that I can get access to, if so which? I don't mind it being under development or if it crashes as long as I can build it and investigate further :)



  • @catalin Hi,

    I have being experiencing the same crashes as @robert-hh when using LoRa MESH with FiPy-1.20.0.rc8, and I know that LoRa MESH has been removed from new development builds such as FiPy-1.20.0.rc13.
    I would like to know if a stable LoRa MESH version is planned anytime soon, or perhaps even a more stable development version?

  • @catalin Thank. That was the trick.

  • @robert-hh, I'm not sure how it works in Android, rights for using Bluetooth and localisation should be given to the Pymesh app (iOS asks when app is first time started).
    Localisation right is required as GPS coords are sent to the node when BLE connection is established; and somehow BLE usage is linked to localisation services, too; honestly I did not investigated this.

  • @catalin BLE Scanner finds both devices active at the moment, but the pymesh app does not connect.

  • @robert-hh

    1. The Pymesh mobile app searches BLE Servers with name "PyGo*". I suppose pressing Restart scan button doesn't solve situation. Try to use another mobile app, like BLE Scanner(or nRF Connect) to check if the Lopy is discovered (it should have 2 services advertised). Sometimes Android+iOS have some caching of BLE connections.

    2. Basically, you can't have your own main, as several threads are in the frozen scripts, hence the zombie threads.

    Now I am working a frozen Pymesh scripts(as library) which can be used with a user config file, hope to be done to be included in next Pymesh firmware release.

  • @catalin Two question:

    1. I tried the Pymesh Android app, but it does not get any connections. Where and how does it search for a connection.
    2. With these standard binary images, how can I change the WiFi settings, e.g. into STA mode and DHCP? The code seems to be executed from If I interrupt is, the normal boot process continues. Funny enough, some of the pymesh stuff continues to run.

  • @robert-hh Thanks a lot, Robert, for highlighting this malfunction.
    I will test this scenario on the latest firmware.

  • @catalin Two things about the crashes: as long as I have at least two devices in the local mesh, it seems stable. Having just one device running causes a crash each time after a few minutes. Normally, the device just reboots and it will start over. Nor perfect, but acceptable. But after a few hours it will end up with a corrupted flash firmware, causing core dumps like the one below. At that point I have to re-flash the firmware. The file system is not affected.

    ets Jun  8 2016 00:22:57
    rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
    configsip: 0, SPIWP:0xee
    mode:DIO, clock div:1
    ho 0 tail 12 room 4
    entry 0x400a05f4
    Guru Meditation Error: Core  1 panic'ed (InstrFetchProhibited). Exception was unhandled.
    Core 1 register dump:
    PC      : 0x00000000  PS      : 0x00060031  A0      : 0x40083b04  A1      : 0x3ffc13f0  
    A2      : 0x3ffc5c6c  A3      : 0x00800000  A4      : 0x00000000  A5      : 0x00000000  
    A6      : 0x3ffdd308  A7      : 0x000006f4  A8      : 0x8008456a  A9      : 0x0000018c  
    A10     : 0x3ffda984  A11     : 0x3ffdda09  A12     : 0x80098d18  A13     : 0x3ffe32b0  
    A14     : 0x3ffda974  A15     : 0x3ffdd304  SAR     : 0x00000013  EXCCAUSE: 0x00000014  
    EXCVADDR: 0x00000000  LBEG    : 0x4009dc28  LEND    : 0x4009dc33  LCOUNT  : 0xffffffff  
    Core 1 was running in ISR context:
    EPC1    : 0x00000000  EPC2    : 0x00000000  EPC3    : 0x00000000  EPC4    : 0x4008b78e
    Backtrace: 0x00000000:0x3ffc13f0 0x40083b01:0x3ffc1410 0x4000bfed:0x3ffe3320 0x40095da3:0x3ffe3330 0x400d2f7b:0x3ffe3350 0x400d2fc1:0x3ffe33b0 0x4015edfd:0x3ffe33e0 0x400e2af1:0x3ffe3400 0x400ddd48:0x3ffe3420
    ================= CORE DUMP START =================

  • @catalin OK. Thanks. It looks like the LoPy4 devices crash all the time. The FiPy seems stable.

Pycom on Twitter