Headless Base Station / Repeater

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Continuing the discussion from Ultra Low Power Nodes:

Still waiting on LilyGo deliveries to start testing. Are headless repeaters possible? I have a vague impression that each station needs to be associated with a phone, but I’m hoping that’s just a bad memory.

What’s the current to mid-term recommendation for base station / repeaters? Specifically, if I buy hardware today, what’s the best bet? GPS wouldn’t be important, but the move to nrf52 and the sx1262 chipsets seem to be a better option, but maybe not available for purchase yet.

Maybe this would be better as a separate thread, but might it be possible for multiple phones to connect to a single node? In a sense, the message would be linked to the phone rather than the LoRa device.

Sorry if I’ve missed this. I know there’s been a lot of development and conversation in the few months since I first stumbled across the project

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Lots of good comments there.

Still waiting on LilyGo deliveries to start testing. Are headless repeaters possible? I have a vague impression that each station needs to be associated with a phone, but I’m hoping that’s just a bad memory.

Yep - headless repeaters are already supported - phone is always optional. But two things should happen. At a bare minimum we need to change the various ‘sleep’ parameters when the node is working as a repeater (this is only settings changes - already stored in device preferences). Eventually there are huge wins on changing our flood routing to be less naive and know that ‘router nodes’ have better coverage than regular nodes and therefore we should route through them preferentially.

What’s the current to mid-term recommendation for base station / repeaters? Specifically, if I buy hardware today, what’s the best bet? GPS wouldn’t be important, but the move to nrf52 and the sx1262 chipsets seem to be a better option, but maybe not available for purchase yet.

I think tbeam right now. Though it sounds like there are a couple of folks working on getting a NRF52 and/or sx1262 boards out. As soon as something like that exists I bet that will be the ideal repeater node (because super low power draw and better radio performance).

I’ve also got a CUBECELL on the way to me. Which looks to be a possible great super cheap/super low power router node. As soon as it gets here I’ll do the small amount of work needed to add it as another supported platform.

Maybe this betterd be a separate thread, but might it be possible for multiple phones to connect to a single node? In a sense, the message would be linked to the phone rather than the LoRa device.

Alas not currently. I made a bit of a mistake when I structured the relationship between the phone and the radio-device. I should have made phones “first class members of the mesh - i.e. nodes just route to them like any other node (except with a much more reliable link ;-)”. This would have let phones have their own assigned node-id.

Instead, currently the phone shares the same nodeid with the radio it is connected to. Which initially made things easier, but as routing has gotten smarter it was the wrong initial decision.

After 1.0 one of things I want to do is fix that architectural mistake.

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Cool. That’s what I have on the way anyway. I’ll just keep on that path and ramp up when the next round of hardware becomes available.

For repeaters, I have to deal with sustained winter temperatures below what most lithium battery chemistries can handle. So I’ll have to try something else, but eliminating that can wait.

But I’m also in an area where there’s no cell coverage, so I have some advantage in getting local community members to join my experiments. I’m not a developer, but I hope to help through the process of getting a network going that solves a real problem for people here.

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What range of temperatures do you experience?

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I’m at 65°N, and -40°F is common. We hit -54 last winter and -63 the previous winter. It’s not uncommon to stay below -20 for a week or three. You can sometimes squeeze power out at those temps, though efficiency/capacity plummets. The rub is that most chemistries won’t take a charge until above zero, and I think we had sustained subzero temps for almost 2 months solid last winter.

And the double-edged sword is that there’s almost no sun, so even running on real-time solar isn’t really workable.

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Wow, what a place! That would be a real challenge I’m sure. Is it often windy?! Only 3 and a 1/2 hours sun to recharge!

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And those 3 1/2 hours of sun are mostly in the shade due to the low sun angle, so aren’t very useful for charging. The coldest months with the least sun do coincide with slightly higher average winds (~8mph). That’s still low for power generation, but smart base station placement on hills should be workable.

At the low end of the power consumption range these devices can achieve, it should be feasible to replace the batteries with supercapacitors. They charge faster (soak up wind and sun opportunistically) and are far less susceptible to cold.

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Yea a bank of super caps could be the way. The size would mainly depend on the expected transmit duty cycle I guess. A busy mesh would need a pretty sizeable bank.

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I could think that the esp8266 could make a good base for a headless device. Paired with a RA-02 module for example it should need less power than a esp32.

Price is nice two. A wemos d1 mini clone goes for $2 shipped, a RA-02 module (sx1278) is less than $4. Combined with a battery or supercap and some energy harvesting device :boom:

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I have 3 D1 Minis, a D1 Mini Pro (also has a charging circuit), and a couple Pycom LoPy4 sitting around. I need to look into installing on other devices. Are there any guides/reports of folks installing on unsupported devices?

Edit: Reading through this thread Discussion on support for custom build targets (i.e. different radio chips, cpus, one off boards)

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I guess esp8266 is one of the easier targets to port meshtastic-device to because it’s the closest to the existing esp32. But I am no programmer so I can’t really tell - for sure it’s still a bunch of work.

Biggest difference hardware wise is the missing bluetooth for the esp8266. As the device can also be completely controlled with USB OTG (works identical with the app and a android phone like when using bluetooth :tada:) their is not really a downside at al. For the use cases as a stationary station/repeater bluetooth is not needed and this can drop cost for building a mesh drastically.

Thinking of $6 (d1 mini + ra-02) and a little bit of soldering for a lora station/repeater :tokyo_tower: is just awesome.

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IMO - nowadays it is never worth it to use a esp8266. The ESP32 is almost as cheap and so much better.

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I suspect the Lopy would be the easiest as it’s in platformio These are probably the files you need to edit/ replicate but I’m new here and don’t really have a clue.

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Inclined to agree. Not planning on buying more, but I do have a few collecting dust. Minimizing similar drawer clutter in the future is exactly why I started this thread. :grin:

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Me too. The esp8266 (and it’s child the esp8285) have a few advantages imho. One is for sure the price - it’s still around 50% cheaper than a esp32. Other thing is the lower power consumption which should lead to a greater battery life. And the fact that many people have them in the drawer could also be a benefit :wink:

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yes - the drawer argument is great. But for most low power applications (unless wifi is a requirement), I think the NRF52 is much better. super low power draw while leaving bluetooth 100% on (< 2mA total - worlds better than the espressive CPUs). So no more of the (painful) sleep/wake dance we have to do on the ESP32.

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FWIW, I hope you spend roughly 0% of your time getting ESP8266 to work. Way more important things, and if the rest of us get motivated to make it work, I’m sure it can be figured out without diverting energy.

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What about wind turbine for charging and heating up the electronics (just like the enclosures of security cameras do)? There are few designs that could work even in such conditions as you have described.

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These turbines are rated to -35c, so may survive even in your temps. You could use a 12v heater element and convert down to 4.2v for LiFeP04 charging maybe?

Personally I’d avoid moving (frozen) parts and go for a massively oversized solar panel with a heating charger on the controller such as this one Then surround the battery system in 40cm of insulating foam.

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all really great info in here. I’ll be following closely, I also live in a rural area and would like to strap some nodes up high in a few trees around here to provide for some basic over/around some hills in the area. I’ve been really impressed with the range in dense trees so far.

curious to hear how the CUBECELL works out. looks like a promising platform. but I haven’t pulled the trigger on buying any yet.

luckily I don’t have the temperature issues that @jetatomic has to work with. It’s just cool and rainy in the pacific north west.

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