$25 low power dev board with solar: Rak4630 (now included in regular builds)

Hi I posted this as a comment already, but think it deserves a thread.

The board is very low power compared to Esp32, affordable and includes 6v on-board solar charging.

I’ve ordered one and will try to get it working, but in the meantime does anyone have one to try/ start work on?


This board is well suited as a fixed Meshtastic repeater.
GPS is not there, but it is not needed for this purpose.
One flaw in her. No version with a frequency of 433 MHz


In my country (UK) and much of Europe you are limited to 10mW on 433Mhz:

Whereas you can do 500mW on 869.4-869.65 MHz

In either case, you are also limited to a 10% duty cycle. I believe this is the same throughout Europe?

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These restrictions are only on paper.
Think for yourself. Who will track what power your transmitter is and how long your signal is transmitted?
The regulatory authorities, especially in rural areas, do not have the technical capacity and resources to monitor the implementation of this law.

Do you really think that due to the fact that the transmitter power will be twice as large, the police will come to you? And will collect evidence of this “serious” crime?


Yes if you want to ignore the law that is certainly true.

My personal interest is in building large permanent installs and I’d need to be legal to do that. If you’re putting equipment on universities or council owned properly they want it legit.


868 suits me, I look forward to following this

That looks like a great board. The existing nrf52dk target in meshtastic is almost exactly the same, so I bet adding it will not be too hard. I’m happy to help with questions.


Any tips on how to build for this board?

Finally ready to look at this again, to start I just need to edit line 12 to nrf52840dk-geeksville?

Then define the pins in a variant here?

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Have u had time to look at this @sam_uk?

In Germany this is well within the capabilities of the authorities. There is a federal network agency called “Bundesnetzagentur” whose job it is to regulate frequencies, create EMF maps with transmitter locations, and to find and mitigate problems. To do so they operate stationary and mobile measuring stations. The mobile stations are usually mounted to vans. You can take a look here:

In other countries this is often done by the military and not that visible to normal citizens. I strongly advise to inform yourself and stay within the regulations for your country!

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I had a play but couldn’t get it working yet. @geeksville is the approach I mentioned above the right thing to be doing?

hmm - I didn’t look to carefully but yeah that sounds like the right approach. Also you might look at the existing “rak815” target - because that board sounds similar.

Looking here RAK4600 EV board does not have USB-to-UART nor power regulator, is this true?

I got two of these laying around and would love to test them out. But wouldn’t know how to modify the rak815 target in order to create a safe build.

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It looks like the “Core” module got upgraded to the 4631 and has BT5.0, and nRF52840 and an SX1262: WisBlock | RAKwireless Documentation Center

There’s a whole host of sensors and things to plugin, like GPS, Wifi, etc.


WOW that looks like a great board/module/archtecture. I’ll buy one.

ooh they have a nice enclosure with solar and everything just clicks together. I just ordered a good cross section of their devices and they should reach me in Taiwan soon.


My work uses the WisLink LX200V20 product for tethered communications. It has one of the lowest failure rates from any of our electronics suppliers.

The more I look at their WisBlock selection, the more I like the architecture. Only plug in the modules you need. Don’t need Wifi? Leave it off.

I would be very interested in making a case for PALS webbing.

@geeksville Maybe see if you can strike a deal through referrals or something with Rak if you can get support added?


Any ideas how these compare with the t-beam? At $44 (base +lora+gps) the TBeams win on price by around 40%