3 Channel LoRaWan Nano Gateway

[jamjam]

Just a random thought that I had, but could you create a 3 channel nano gateway with a new baseboard with 3 slots and 3 LoPy's. One acts as the TTN WiFi master collating all the data from the 3 channels. A proper gateway and still lower cost that other options.

I say this as I have to heavily modify my RN2483 settings to get it to com with the LoPy nano gateway. I would rather not do this so I can test with deployment settings.

Spec suggestions...
Master & 2 slave slots, use 2 pins to set 00, 01, 10
Same firmware for all LoPy, use GPIO to set mode (master, slave0, slave 1)
Use SPI to com from master to slaves
GPIO int back fro each slave to indicate packet reception
USB connection to master slot only. or jumpers on serial
Reprogram LoPy by unplug and place into master slot, or use jumpers ...

[jmarcelino]

@jamjam
In the last Kickstarter update they said end of Sept, but let's say 2 months.

[jamjam]

@jmarcelino how soon is soon?

[jmarcelino]

@bmarkus
Indeed.. not for the LoPy but for another Pycom board coming soon starting with G ;-)

[bmarkus]

It would be interesting to connect a SX1301 board via SPI to a PyCom ESP32 board like WiPy2 (LoPy my work but LoRa modem would be useless) and make a 'real' GW.

[jmarcelino]

@jamjam
Yes the RAK831 is a full LoRaWAN gateway board and uses the same chip as all LoRaWAN gateways (Semtech SX1301) so it does all the necessary LoRa channels in all spreading factors

[jamjam]

@jmarcelino thanks for the heads up in the RAK831, think your right this would be much better. 9 Parallel demod (LoRa) paths from what I can see...

[jmarcelino]

@jamjam
You can buy a real DIY gateway (RAK831+Raspberry Pi) for about £150 these days, not sure the savings are worth it.

Single channel is still interesting though.

[jamjam]

@bmarkus fair point but for a debug setup £90 is very attractive attractive price point.

[jamjam]

@jmarcelino good point, I like this, though I was thinking if you used one as master you could avoid issues regarding point 2

[jmarcelino]

@jamjam
There's no need to collate the data, just register the 3 LoPys listening on different frequencies as 3 gateways with TTN

Also it's better to keep the LoPys well spaced apart (and use Wifi) because:

1. Multiple LoPys combined into a single board would count as a single product which would have regulatory (FCC, CE etc) problems

2. The Radio receive path on LoPy the is extremely sensitive so if one of the LoPys transmits it would the affect reception in the others that are close by overloading the amplifiers, if it's too close it may even damage them. It's best to keep your LoPys apart by a couple of meters.

Real gateways avoid this by physically (via RF switch) preventing reception while a transmission is taking place.

[bmarkus]

Even if you have 3 LoPy's, one per the mandatory channels (expecting EU868 band plan, US915 is more complicated), it will not fulfill the requirement that these channels must be Multi SF and e.g. you can't use ADR. If you need GW, use GW.