Raspberry Pi Based Node and Gateway Hardware Suggestions

End Devices (Nodes) Hardware
1

Hi Everyone,
First, thanks for starting and contributing to this project. I think LoRaWAN has some huge potential and it’s great that so many people are already contributing to bring this technology to mainstream.

I’m new to the project but I’d like to setup a gateway and node I can use to try it out and learn more about the platform. I’ve read through the documentation here and elsewhere about setting up gateway and node hardware. I wanted to summarize my plans for ordering/building gateway and node hardware so others with more experience can comment about information I might have missed or other things I should consider.

My plan is to use the Raspberry Pi as the platform for both the node and gateway as I’m already familar with this hardware/software platform and I’d like to be able to re-use as much of the hardware as possible between implementations. Cost is not a big concern on either side at the moment as I’m just trying to put together a demo platform.

I’m in the US, so I’ll be using 915 MHz.

Here are my thoughts about the hardware I would order for the Gateway and Node.

Gateway
Option 1: Purchase the LoRaWAN Raspberry Pi Gateway Board. This looks like the easiest to setup, however it’s currently sold out with no ETA. I’ve sent an email about availability. It looks like they are waiting to run more until they get hardware feedback in this forum thread. Total solution cost would be something like $275 with a $10 antenna and $35 Raspberry Pi. Software would be based off of whatever the folks in this forum thread are using, probably ttn-zh/ic880a-gateway. This would be my preferred hardware solution depending on estimated availability.

Option 2:
Use the instructions in mirakonta/lora_gateway to build a gateway based on the $170 MTAC-LORA-915. The original USB to Mini-PCIe card referenced in this article is no longer available, so I’ll need to order this one for $8 instead. Hopefully the hardware hack mentioned here will still work with the new board. Adding in the same $10 antenna and $35 Raspberry Pi brings solution cost to around $230. Software will be based on the github repository at mirakonta/lora_gateway

Node
I found a nice article here comparing Raspberry Pi node build options. I’m thinking my best bet is to wait for availability of the $15 Modtronics SX1276 which should ship sometime in March. This gives me the benefit of using the SX1276 and higher output power. Adding a $5 Antenna and $35 Raspberry Pi brings solution cost to around $55. .Software will be based on the repository at mayeranalytics/pySX127x.

Thanks for reading. Any comments or suggestions are much appreciated!

2

An update on this for anyone who might be interested based on new info I’ve learned since posting last week:

Option 1: Purchase the LoRaWAN Raspberry Pi Gateway Board8. This looks like the easiest to setup, however it’s currently sold out with no ETA. I’ve sent an email about availability.

I didn’t realize/notice before that this board is only available in 868 MHz. I’ve emailed with the folks at Link Labs and it seems like the only option for 915 MHz at the moment is their LL-BST-8 gateway which does not appear to be based on open source software.

3

Hi - just to get some conversation going, I’m about in the same situation - have been playing with a pair of HopeRF RFM_95W from ebay and just got a pair of the Modtronix inair9b. Also have been working with Congduc’s low cost gateway, currently using an RFM_95W / RaspberryPi with the software slightly modified and for the node a Modtronix module with an Arduino Pro Mini (love those!) and a ds18b20 temp probe, testing Lion battery life w/ a high efficiency 3.3v buck converter.

For a real LoRaWAN compliant gateway I’m considering the MTAC-LORA-915 project, still on the fence however.

4

Thanks for the reply!

One development since my last post, I spoke with a person at LinkLabs, they mentioned it’s possible to change the SAW settings on the LoraWAN Raspberry Pi Gateway to setup the SAW filter for 915 MHz. I’m going to try to get more information about this, will post here when I do. Ideally I’d like to see if I can get the schematic prior to ordering. They also pointed me to the github project here which targets their Raspberry Pi Gateway and which was introduced in a forum thread at http://openlora.com/forum/viewtopic.php?f=4&t=36.

I’ve also spoke with Multi-tech about the MTAC-LORA-915, they confirmed that they believe the plan to use this card with the instructions at mirakonta/lora_gateway will probably still work.

5

Been watching the digikey stock of MTAC-LORA-915 - dropped from 19 on March 3, 2016 and now down to 10 on March 16 :smile:

6

This March 16th 2016 blog post from Andrew Back, who seems to be working on the Flood Network with @lovehz and others, might give you some ideas for an iC880A -based multi-channel gateway: Building a Raspberry Pi Powered LoRaWAN Gateway for TTN Calderdale.

Also, A DIY low-cost LoRa gateway by C. Pham uses a Pi for a single-channel gateway but that does NOT (yet?) support the LoRaWAN data format.

As for the nodes:

…they now state “We will soon release two new versions of this module, one with an U.FL connector, and one with an integrated (onboard) antenna.”

7

I’ve clarified this comment with LinkLabs, it’s not possible to change SAW settings with their current hardware design, so Option 1 in my initial post is out for me now until/unless they come out with a 915 MHz version.

I’ve looked around today and noticed a new option in the Calao Systems Toti-LoRa-pico but no informaiton about availability or confirmation that it can support 915MHz. I’ve sent an email requesting availability information.

If I don’t see an update or get a response it looks like I’ll be moving forward with the “Option 2” MTAC-LORA-915 based solution.

8

dwalkes , have you found a solution? I am in the US and interested in building a gateway. I am curious if you have found a good option. Thanks!

9

Hi Rob,
I ended up going with option 2 in the original post, my gateway is running using the instructions there although I haven’t been able to test it with a node yet.

The Node has been more challenging. I’ve purchased the Modtronics SX1276 but I’ve learned the software repository mentioned in the node post isn’t an actual LoRaWAN stack, so I’ve been working to port the existing LoRaMac-node repository to the Raspberry Pi platform - see work in progress here on my add-pi-target branch. Code is compiling and running but communication between node and gateway is not yet working. I’ll post another update when I have it working or if anyone would like to help I’d appreciate any assistance there.

10

@dwalkes How straightforward was the tutorial you posted for option 2 to follow? Did you have to modify the USB to Mini-PCIe card any differently than from what was posted in the original tutorial?

11

See also

https://www.thethingsnetwork.org/forum/t/the-things-network-raspberry-pi-hat/2959

12

No, I just followed the tutorial. It makes sense when you look at the pinout and the traces on the multitech board.

13

A post was merged into an existing topic: The Things Network Raspberry Pi Hat

14

I’m planning to do RM191 Node with your Option 2. Did it work out fine or MTAC cooked with overheating? From the sound of it, any Mini PCI-E will do if the pins get wired according to tutorial to make a shield instead of USB and power it from Pi? or does it actually need to be USB?

15

Hi,

Did it work out fine or MTAC cooked with overheating?

I had power supply problems with the Mini PCI-E card I bought. The 3.3V output was dropping out on the regulated side, dropping down to 2.7V after starting to transmit from the MTAC. I ended up pulling up the inductor on the board and connecting to a benchtop power supply instead.

From the sound of it, any Mini PCI-E will do if the pins get wired according to tutorial to make a shield instead of USB and power it from Pi? or does it actually need to be USB?

I think you’ll need to use a USB converter because you need the USB connections for the FT232H and you need analog power input on pins 23 and 25 which would typically be used for the express lane on a Mini PCI-e slot. See comments here for details. Let me know if I’ve misunderstood your question.

16

That explained very well, thanks. It’d be nice if someone did a breakout board on PCBs.io for this with proper power regulator and pin connection (23,25)

Are there any better quality Mini PCI-e to USB that’d do this job without bench top power supply? I need this to be portable to plug it into any outlet, can’t take a bench top power supply.

17

Probably, I haven’t searched or tried any others.

Note that I still haven’t been successful in actually getting bi directional transmit working with this solution and the hardware I bought. It would be great if others tried it but want to make sure I’m not giving you a false impression this setup is going to work.

18

Thanks, lots of great feedback. I guess, it’s not exactly out of box ready to go type of setup equivalent of having the conduit.

19

I haven’t been able to get the mirakonta fork working fully, either. I was able to get transmit working by disabling some error handling in the code and fiddling with frequencies in the config file. I’m using a mirakonta style gateway, and an adafruit m0 feather at 915 MHz. Anyone have similar experiences? Secrets to success?

20

I just revisited this today and it looks like there is a new gateway option from this thread which looks to be exactly what I was looking for in 2016. See purchase link.