Meshtastic

Building for NRF52 boards

Just wanted to create a separate thread for this open source board based on an nRF52840 and ebyte sx1262 SPI modules. It was developed before I knew about meshtastic and has a ton of advantages such as:

  • great always connected bluetooth implementation,
  • 8dbm tx power for BLE,
  • Adafruit nrf52 Arduino core compatibility (Feather nRF52840 bootloader),
  • Native USB,
  • superior Lora Performance,
  • higher lora tx power options,
  • compatible with SX1268 433mhz modules,
  • really low power consumption,
  • IPS Screen with many pixels (ST7735-based),
  • GPS Option (BN220 etc. With high side power switch)

Kevin is planning software support for this combo already. 3D printed enclosures and an updated version will appear soon.

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Very good starting point, supports threading and features an inner cryptocell for advanced cryptographic functions.

Sounds like a great board. And yep - both this processor and radio have alpha level support in the project. (Though of course someone who has one of these would have to add other board gpio assignments and test).

Also a driver for whatever screen you used would need to be added, but that is fairly painless.

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Great! I really have to understand Platform.io and the project structure as I have never used it before. Desperate lack of time at the moment.
Is the Bluetooth comms part hard to port from ESP32 to nrf52?

Not super hard - just needs three characteristics implemented. Alas, I just haven’t bothered to do it yet. I’ll get to it soon though :wink:

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Here’s some build instructions (though I also like their IDE):

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Neat, as a pretty heavy Arduino user I gotta try to wrap my head around this whole platformio system on the weekend or so. I installed the IDE and looked around in the project directories a little. Are you actually making use of that nRF52840 crypto engine? Does that work?

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I looked at the docs for that crypto engine and it looks neat. The library we use for crypto (on all platforms except ESP32) does support that engine, but we don’t use it because:

  • I was lazy and wanted to make a solution I could also use on other ARM chips
  • Our packets are small and infrequent (from the CPUs standpoint), so using the CPU to do crypto isn’t too expensive
  • Someday if there are boards that users can buy that have the nrf52840, we can do the (smallish) work to support the 840 crypto chip.

On ESP32, since they had a nice easy library for using their hw crypto - we do use that hw engine.

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I understand.
It’s only a matter of time until some chinese people discover and mass produce this :smiley:
Makes me wonder why there a 200000 almost identical esp32/8266 boards and so few convenient nrf52 platforms. It’s a shame.

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Another nice thing with the nRF52 is it comes with support for NFC tags.

I’d love to see an easy pairing process (no screen needed) with smartphones just by tapping.

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Ok, so let’s break out the NFC pins

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I prefer Reticulum way of pairing, where nodes are all equal and it is the entity to possess and exchange keys.

In fact - I don’t know anything about the RF/layout requirements for NFC. But I wonder if you could do the “poor man’s solution” and just feed the pins out to traces shaped properly to be a (marginal antenna). Because it only needs to go a couple of cm to the phone (and only a few bits very occasionally).

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I’ve done it once for a nrf52832 some time ago. I think it requires 2 100pf caps and the coil. the latter could also be connected externally to save board space.

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Hi Corvus, I’d be interested in trialling/assembling a nRF52840-based board with Meshtastic. Do you have a stable board at this stage, or are there revisions planned soon? While I can do some assembly, I’d prefer a largely made-up board.

Andy

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Hi, the board is ok so far but the design files on github need an update. I’m already working on a v1.1 which contains bug fixes and some minor improvements. Problem is that it will take another week or so since I have no access to my eagle PC at the moment.
Already thinking about a v2 which will be more similar to the t-beam with an 18650 holder and some addons some forum members suggested.

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Sir, good morning!
I am ready too to start tests with on U-BLOX NINA B302 (NRF52840) modules and publish a lot of blogs about.
Some questions:
-Plans to implements mesh using only the BLE RADIO ? It´s a long range radio.
-If not, will it work with https://proesi.com.br/arduino-modulo-lora-1276-915-mhz-100mw-ate-4k.html ?
-If not, do you have the schematics to connection with SX126 ?
-Is already compiling to NRF52840 ?

I can help you on NRF52840 tests.

Miguel

I got this error during NRF52 compile

btw, we think to use your mesh network in a 60Km farm to get few data packages from 50 remote point to collect data.

Is that possible ? we can install more that 50 nodes if necessary to get a good mesh

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alas - the NRF52 targets are not yet officially supported. But I’m working on cleaning up the NRF52 build soon so that it can be easily used by others (in the next couple of days?). I’m working with Nick Zambo on the #rak815 chat on this - can you join us there? (See slack invitation in the pinned Development post)