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

A friendly advice to always attach the antenna before powering up a radio. If it tries to transmit and there is no antenna it may die.
Has anybody done any power calculations if the small solar panel i see on their box will be enough to power a meshtastic node?


Here’s a somewhat old spreadsheet with measurements of a nrf52840 + GPS + rx1262. This new board should be similar bug I haven’t verified this yet. Sometime in the next few weeks I will.

The interesting parts are to compare link 54 with line 72.

If someone could look into the datasheet for the RAK solar and add a line for that solar panel I’d be greatful (just request editing permissions).

I’m so glad it was not fragile… mine is in the way…

I think we all do “think for ourselves”, but many likely do not say certain things “out loud” online where what they say is 1) around forever 2) easily searchable for use anytime in the future.

Do you announce to the police officer standing by the side of the road that you are going to exceed the speed limit or drive carelessly? Maybe you do. That is OK if you do. But, to suggest folks are not “thinking for themselves” because they choose not to do it and simply go about their day without announcing that they’re driving 2x the legal limit isn’t quite accurate or realistic. In fact, I’d say they’re thinking more clearly than someone who records it, posts it on YouTube, and sends local law enforcement the link.

Some folks just don’t openly announce or discuss their intent to break laws, especially ones (that at least in the US) can have serious consequences (felony) if you get caught, even if the chances are very, very low (they’re quite higher than I think you recognize, but I’m not going to try to change your mind on that).

I ordered the Wisblock starter kit ($25 USD) and it took about a week to get here in the US. That is really impressive! It definitely is a step up in quality. They included the Lora and BLE antennas and even a short USB cable. I can’t wait to get this loaded up and test it out.

Edit: Loading it was very easy as outlined above with USB. It does not include the jst 2.0mm connector for the battery or the jst 1.5mm for the solar panel. I ordered a few so it will be USB powered until then.

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Yall who have gotten hands dirty with these Wisblocks. Could a Wisblock use two cores? So we could have a node with two radios? Use cases bandwidth scalability and PTT voice.

Mine is on the way. To help with this question I posted this to the RAK wireless site as a help question. I will keep you posted on the reply…

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Answering my own question, no: https://docs.rakwireless.com/Product-Categories/WisBlock/Quickstart/#hardware-setup

You can install our release binaries by “drag-and-drop” onto a special simulated “USB disk” that appears on your computer while the device is in the bootloader. To install:

  1. Enter the bootloader by removing all power (including the battery), then connect the device to USB. For the first 30ish seconds after connection the device will wait in the bootloader (before starting any application that might be loaded)
  2. From our relase zip file, drag and drop “firmware-rak4631-xxx.uf2” onto the bootloader “USB drive”. The drive will be named “FTH…BOOT”
  3. That’s it. The device should reboot and start running meshtastic.

Just got a chance to plug in my RAK starter kit with the 4631 board. Oddly enough, it doesn’t appear to be exposing a volume to transfer the firmware. It just shows up as an ordinary USB to serial device. I am on a windows box at the moment. I may try it on my linux machine a bit later.

Edit: Never mind. I found a post on the RAK Wireless community. After you connect usb, just double tap the reset button to put it in bootloader/UF2 mode. :partying_face:


Tempted to purchase a few of these. I have access to a few high points around London which I could permanently leave these and help build a router network in with the solar enclosure.


Hi @Ben360

How far west do you think they will reach?

Given Basingstoke is in a dip I doubt it will make the 75km but maybe Bracknell at 44Km is a little closer when the office opens up


It might be wrong polarity, the screen printing suggests positive is closest to the edge but I found a photo of red inside.

I dug into the datasheet of the base board, apparently the triangle points to the ground pin.

This is reportedly true of the solar connector as well.


Posted some of this in a thread in the Slack chat, but I thought I’d share it here as well in case it’s helpful to anyone else:

I’ve been interested in running a RAK board on 12v solar without the cost and space requirements of a dedicated solar power management board. The problem with running a decent 12v or even 5v nominal solar panel directly into these boards is that RAK has a max rating of 5.5v dc in for the solar port. I have run 5v nominal panels that in full sun under a load can easily punch up into the 8v range.
One thing I found when I was looking for an appropriate and reasonably priced 5v dc regulator was this Murata dc-dc switching regulator in an old arduino thread:
It supports 7-36 max dc voltage and regulates a fairly clean 5v out. My only concern with these is how they behave with under-voltage, since that’s a given with solar power once darkness hits.

I experimented with my bench power supply, and it doesn’t appear to “jump” any higher than the regulated Vout as some switching regulators reportedly do. It sags a 1-2 volts lower than the Vin, which should be fine with the RAK board’s solar input. I don’t currently have an oscilloscope to say that with 100% certainty there isn’t a high voltage blip that occurs for a few nano seconds. I doubt there will be anything potentially damaging coming out of it though, especially with a capacitor across the terminals. So I’m hopeful I can slap just one of these new RAK boards with a murata regulator, a cap and a battery in one of my solar panel mounted junction boxes instead of relying on a whole external solar management system.

For those that have the full WisBlock solar kit, has anyone been able to real world test it to see if it can keep the battery and device going through some normal usage patterns? I have to admit, even as low power usage as this board boasts, I’m a bit suspicious of that tiny solar cell being able to keep things running long term, especially if you’re deploying it in a region that isn’t blue skies all day.


These boards are inexpensive, pretty small, adjustable, efficient and work well. I just haven’t tested them for EMC yet.

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You could perhaps order several zener diodes and bench test them to put one across the solar panel. In theory that would help with your concern and lightning both.

I can confirm this. I had to switch the pins in my JST connector. The triangle does denote negative for battery and solar.

Happy to range test it. Let’s see how many s.e folks we can find and make a mesh network :slight_smile:

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Looks like RAK is aware of the Meshtastic compatibility, they updated their docs for how to upload MT firmware: RAKwireless Documentation Center

Congrats! Hopefully a deal was made. My order finally shipped after more than a month of waiting on standby.


My Wisblock Kit 2 arrived yesterday. Some initial impressions:

-The solar panel is not adequate to run the board even in direct sun. I do have the GPS block installed and anatmospheric sensor installed. Not sure if perhaps the panel would be sufficient to run just the base board with the LoRa module and without the GPS module, but being that the kit includes the GPS, it seems like it should.

-The box is very…clinical. No passthrough for the reset button, but there is an opening for a USB cable. The lid on the box has no gasket. Should be no time before the 3D printing community has a more user friendly case design uploaded.

So far the operation is good. “Meshes” well with my mesh. Pun intended. The phone app plays nicely with it and even shows an RSSI value for each node on the mesh. Pretty neat.


On my boards the Battery Ground indicator was correct, and I could plug the battery straight in.
On the Solar connector, the ground indicator arrow is wrong, but the plug is still correct, so again I could plug the solar panel straight in, but the silkmask then suggests that the polarities are swapped.

@thebentern is the battery charge reporting correctly for you? I get an NA when running meshtastic --nodes for the RAK boards - I dont have a screen for them so can’t say if the info isn’t being sent or isn’t measured.

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