Guys, I’m now working on the ultimate RAK4631 compatible board.
For now, I plan to produce two versions of this board for each form factor.
Base: RAK4630 with external hardware watchdog, connected via USB bus to the host. It’s just RAK4631 inside your PC/Laptop/Router/Raspberry PI.
Ultimate: RAK4630, hardware watchdog, BME250, GPS with Dead reckoning (position without satellites), and LAN connected via ethernet-USB to your host. It must be a pretty universal device! It’s can be used as a gateway, assets tracking device, and of course just a repeater/or telegram gateway.
Yes, it must fit all laptops with a WWAN/3G/4G/LTE slot.
But some vendors may restrict the usage of third-party modules. You need to check it first.
For example, as I know you can’t insert third-party modules into ThinkPads without BIOS/EFI modification.
Because such a card would sound interesting and I have the 4G Module in my L14 and haven’t used it yet. So to swap that for a way to communicate to Meshtastic nodes without having one next to the laptop sounds great
Wow The modem will take a significantly longer time to appear on the USB bus and the firmware will “miss” the modem at boot time.
We got a chance, I have T460 in my home and I can test how it really works for RAK MCU and LAN7850 chip. Of course when I got M.2 module in hardware.
Our “RnD team” finished with the board and circuit design.
We replaced some IC in the Watchdog circuit and Power Delay module.
So for now we got a startup delay of about 3s (thanks @roland for the suggestion) for bypassing (I hope) the vendor’s hardware validation. Also, the watchdog reset the RAK if we don’t have led blinking about 25s, and we now have much time for Meshtastic boot or to bring the device to DFU mode.
I already start ordering hardware components to bring to life the basic version of the M.2 board.
If all goes fine with testing the basic design, we switch over to producing and testing the Ultimate version of this bad boy. And only after that, we should try to fit this design into the Mini-PCIe board.
Serial tty should probably be okay. Haven’t really tried any of the ATAK Stuff myself. I’m still in the planning and analysis phase in order to figure out what exactly I want/meed to setup, from clients to servers and routing nodes/trackers in between.
What frequency LoRa are you using? Here in europe 443 and 868 are legal, but from what I read (on here) 868 seems to be superior (and would match my t-beams - that I still haven’t really tried since I got them )
I plan to produce the first bath with RAK4630-H chips, it supports all 868-915Mhz bands.
If you need devices with RAK4630-L chips (more than 5) I can order these MCUs. But keep in brain, the antenna in your laptop must be incompatible with this frequency range.
I’m talking about the 433 Mhz range =) with 868-915, it works fine, I’ve tested it with my old ThinkPad X201, embedded antenna works like a standard 3dbi antenna included in T-Beam.
Today factory started production of our test batch of M.2 cards, If all goes fine with SMT I hope I will get this batch in the second week of march and start testing these boards with my home Lenovo laptops.
After sanity tests, I discovered issues with the Reset-delay circuit:
It’s not working, looks like something wrong with the capacitor/resistor
I do some tests in my Lenovo T440s, and discovered startup delay for 3s must not work to bypass UEFI checks. Because my laptop booting to an unknown device message about 25s.
Also, I found issues with wiring the USB2412 hub, looks like we got incorrect wiring of OCS_N1 and OCS_N2, now it’s attached to the ground, but in our case, it must be just not connected.
Also as you see, JLCPCB ordered the incorrect RAK module with an IPEX connector, It’s fine for tests, but can’t go to production. I tried to reorder the correct RAK4630 variant via JLCPCB but got the minimal quote from RAKWireless for 458 units, it must cost about 8K EUR, so it’s mean I can’t continue with RAK4630 without any investor or crowdfunding…
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