Meshtastic

Building for NRF52 boards

I’ve just retitled this thread (and using this post rather than the RAK815 channel @ScriptBlock and I have going in Slack because I want this to be persistent and searchable):

So I just did a fair amount of arduino/nrf library plumbing so that the various NRF52 based boards can ‘just work’ and build in platformio without needing to make symbolic links or apply other hacks. I also cleaned up some bitrot that had crept in - where code was assuming ESP32 when that isn’t always true.

These changes are in the “post1” branch on meshtastic, This branch is where all features/work that are after 1.0 will be applied (I’m doing this NRF52 stuff now to help out @ScriptBlock on getting his RAK815 board working, but I didn’t want to break anything in 1.0).

You should now be able to build for nrf52840dk or feather_nrf52832 boards and platformio will automatically pull down all tools and dependencies that are required.

I’ve updated the continuous integration rule on this branch so that it builds for the four most different targets we have (“platformio run -e tbeam -e heltec -e nrf52840dk -e feather_nrf52832”).

Tomorrow I’ll get the adafruit bootloader running on the RAK815, then work on getting the RAK815 so it runs all the usual meshastic goo.

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This is awesome. Thanks for the efforts.

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Great!! Can’t wait to try it out…
I updated the 30dbm version of the board to v1.1 and uploaded the new design files. The design has not been tested yet but it should work.

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Does v1.1 already have all the features we discussed?

No, not all. 2.0 will have em all, but it will require a complete re-route and re-arrangement of the components. It will also be larger in size.
1.0 was not fully operational without bodges so 1.1 is more of a debugged version with some extra features.

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Hi Corvus,

Interested in your board design, I live in china, do you need cooperate? I can hand solder and gather sample parts much quicker if you are not near Shenzhen.

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The design is open source and you can use it as you like. It’s really nothing special, some modules glued together and some housekeeping :wink:

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Thanks for your respond.

I am looking at the BOM for v1.1 and start sourcing the parts. I will check PCB next week for pricing. First batch I will make 5-10 pcs. I will donate 2 pcs to you if you are interested.

Est cost maybe around 50 USD, they are expensive modules on board. once the firmware branch is mature and demands exists, cost may could drop 30%-50% but some RF considerations requires which will take time and expertise.

If anyone else is interested in testing the first 10 pcs, please leave your message. I don’t have an idea how long the shipping will take right now or even possible, so please leave your shipping destination or PM me.

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Nice, I think it makes sense to donate a board to @geeksville as he is the main software developer.
Sorry for not including the BOM, I usually don’t bother because I share the schematic and from there pople can extract most necessary components.
I’m planning a v2.0 which is supposed to be powered from one or even two 18650 cells and include more cool stuff such as an SD card holder, more room for GPS, a sunlight-readable always-on screen, improved power management and safety features for autonomous solar charging mode, NFC antenna connector etc… This will be a re-design and should take me half a week to develop as soon as I have the time.
Do you really want to produce v1.1 now or better wait for the next rev?
I think the RF part on the PCB is trivial here because we are using modules with everything on board. Or do I overlook something?

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If anyone sends me hardware I’ll happily try and help make it go. :wink:

@Corvus Let’s make a small step at one time, I’d make the v1.1 board, I have a ublox m8q module which is very small and stacked with ceramic antenna. For GPS I recommend use cable or FPC to move the unit further from MCU(EMI concerns) , and also allow more options for its location inside a shell.

Please consider making new hardware more modular: the basic comm part, RPI-zero (for Postgres GIS), MPPT solar module, NFC and NFC antenna module, PA and RF swithing module for long distance etc, and choose connector for user can easily stacking the modules they needed (like a cubesat but much smaller profile).

@geeksville Sure thing.

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Can the screen be disabled software-side? Or just create a version without LCD, for headless nodes

Meshtastic software is made for low-power embedded uC like the ESP32 or the nRF52840, a raspberry pi is an overkill. Any relatively-new smartphone can perform GPS data analysis if needed. Regarding LoRa modules, ebyte has got quite a huge choice, they all have the same form factor and use the same communication protocol (SPI), I’d leave to the maker to decide which module to use according to their specific needs.

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@Anelito, when talking about RPI zero is about a standalone local map server, which you can use a dump from osm, add your own layer and planning routes, without any map pre-fetching or data network.

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Hi, I spend some time checking the design of SX1262 v1.1 on github, here are some questions I need to ask for help:

  1. G5177C R18 value is not specific, 0-5 Ohm?
  2. Would you please double check the voltage network for G5177C, just for make sure, I want to pop all parts on board and really don’t want to smoke them.
  3. nrf52840MOD, aka Holyiot-18010, have different numbering scheme other than your library, just a reminder, please double check if pin definition if you have time.
  4. a missing value for a N-MOS, Q1 = ?
  5. U$45 is not a switch ease to source, would you please add a soldering jumper pads on PCB?

That’s for now, please have a check if possible, thanks.

Hey, sorry for the inaccuracies.

  1. R18 is 4.7 Ohm
  2. The resistor network was fine-tuned and the values are correct to output slightly more than 5V to have maximum output power.
  3. As far as I know only the two designated pins are swapped. Everything else seemed to be fine in my tests of v1.0
  4. Q1 ist not critical. Just some logic level Nchannel Mosfet. I use SI2302
  5. https://m.de.aliexpress.com/item/32770868105.html?trace=wwwdetail2mobilesitedetail
    These are all over aliexpress

Thanks for the clear explanation, I will try to tapeout PCB tmr.

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Sorry for one more thing which more related to Eaglecad which im not familiar with, after pouring the polygon (rastnet?) it seems the distance between trace to the plane is about quite small, I could figure out the size but according to grid it looks like 0.12mm? I sees not viable for cheap 2-layer testing or did I get it wrong?

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I ordered v1.0 boards from oshpark and they worked well. You think other board houses don’t get it manufactured?

Maybe I got the dimension wrong, I will double check against manufacturer’s manual.

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