Chirpstack Gateway OS with two concertrators

ChirpStack Gateway Mesh
1

Hello,

I wonder if the current Chirpstack Gateway OS supports dual concentrator board, where both are 868Mhz over SPI interface? Is it handling the SPI device reset for both boards?

In the change-log I see there is support for RAK7268 multi-slot, but that is for 2.4Ghz. I am using mainly RAK5146 module with RPI CM4.

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What I am interested is to use Slot 2 for mesh with directional panel antennas (so I can relay the uplinks more effectively), and use Slot 1 for end-nodes with omni antenna.

I see in Chirpstack Gateway OS there is an option to specify the Slot. Will it work out of the box? What GPIO pin I need to use for resetting second Concentrator?

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1 Like
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I briefly tried this with a dual slot RAK7289V2, both with 868MHz concentrators. I was going to use one for relay ↔ border traffic and the other one for node traffic, but couldn’t get it to work with both concentrators enabled. I didn’t spend much time on it though so I may have missed something on my side.

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@John_A that will be very interesting to see it work. This way, LoraWan network can be build similar like mobile operators > you will have dedicated relay links and dedicated end-node antennas in one Gateway (opposite to relying on network connection on each gateway).

It is technically already possible thanks to mesh feature, but adding directional panel antenna gives you more range (but narrow coverage), while using omnidirectional is perfect for collecting end-node data (but it comes with compromises).

I am waiting for panel antenna to arrive and could test it soon, but was wondering if anyone did it already :slight_smile:

1 Like
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Very interesting and promising idea. :smiley:

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This was implement to support some of the RAK gateways. They have multiple slots that provide unique SPI and / or USB interfaces. So each module has its dedicate SPI device path or USB interface path. It also provides an unique reset pin per slot.

This is also supported for the CM4 in combination with the RAK7391.

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@brocaar do you know by chance which RPI GPIO pin is used to reset the second SPI device? f.eg by default it is GPIO17. I wonder which GPIO is used to reset second SPI (concentrator). I will need to trace the GPIO pin from RPI to the second SPI reset pin on my PCB.

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Greetings,
I am also thinking to ask same question on RakWireless forum, but since I will be mainly using ChirpStack GW OS, perhaps this question is more suitable here?

SPI Slot 1 Concentrator > Reset pin: GPIO 17
SPI Slot 2 Concentrator > Reset pin: GPIO ?

I have see in ChirpStack GW OS that it might be possible to change the reset pin manually in “etc/config/chirpstack-concentratord” by adding:

option sx1302_reset_pin ‘14’

but I dont know how that works with 2 SPI devices/concentrators.

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I guess this is what you are looking for:

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thanks @brocaar looks the right one. Let me try it

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