Back to Smartcitizen.me

GSM / LoRaWan connectivity

Hi,

Our #viadukaduk sensor network is still running. Part of the maintenance is going to locations updating network wi-fi information. You wouldn’t imagine how often our volunteer sensor hosts change ISP or simply wi-fi passwords. This gives a ton of unnecessary maintenance.

At the same time we are looking for a grant to enhance the network and analyse the data properly. There is something on the horizon… Fingers crossed.

Therefore, given budget might become available, I wonder what could you advise me in terms of gsm internet connectivity. How do I do it?

I can’t advise on an exact method, but in principle what you need to do is provide a communications gateway between the Wifi supported by the kit and the 2g/3g/4G/5g network.
The “out of the box” method is simply to purchase a commercial gateway of the type made for home use by several manufacturers. You buy the gateway and a sim to suit the network, then configure the kit to use the Wifi network it supports. Then pay ongoing data usage charges.
This method has the advantage there are no modifications except for the config need to change inside the kit.
But the device will need to be powered in addition to power for the kit.

There are other ways too but they all need you to modify the kit firmware and hardware.

Thx. Brynn. It has to be integrated within the arduino. Otherwise it’s clumsy. Something like this:

@oscgonfer @victor

Hi do you have anything to share about gsm?

Hi @bron,

I do not have experience with GSM in particular, we are exploring options for future versions of the hardware, but for GSM itself little I can say.

However, in terms of access points as @bryn.parrott says, there are plenty of options out there. Some openwrt options by GL.iNet are quite inexpensive. We normally use this one: https://www.amazon.co.uk/GL-iNet-GL-AR300M16-Ext-external-Pre-installed-Performance/dp/B07794JRC5?ref_=ast_sto_dp, which is easy to configure and has a simple ethernet port. For more options, a 4G router with a SIMcard could work (and we have done it too: Smart Citizen Connectivity Units - Smart Citizen Docs) but it means you need a prepaid data plan, which might not be as convenient.

Bringing the question back to @all: how valuable would you deem having something like a port in the data board to connect to a SIM900 chip via the ESP, for instance?

Ok

I have accepted the current method of external connectivity beyond wifi: by having a device that communicates with the kit via wifi and no other wiring needed except for power.

However as @bron has said, and I agree a more ideal solution would be to be able to swap out the Wifi connectivity with another board that provides external comms for remote situations.

. Having only wifi as the only solution is limiting I feel.

There are a myriad of different remote comms networks these days:

  • mobile phone networks 2g/3g/4G/ 5g and soon enough 6g
  • LORAWAN
  • various flavours of LTE

The mobile network is ubiquitous worldwide and there are modems available that can work world wide with the correct local SIM card.
LORAWAN works in a few countries but not everywhere just yet.

So an ideal solution is a plug in slot that allows various modems to plug in. I do not know how this would go with firmware support but there are a couple of chip makers that sell a range of modems with mixed capabilities.

The device mentioned by @bron looks good and I’m tempted to look into it myself.
A key requirement is for such a device to have a library available that will run on the samd21 platform and be easily integrated as an alternative to wifi.

I can say that for certain the current wifi esp8266 device is deeply embedded in the firmware design and it will not be terribly easy to abstract the comms part and devise a means to have the firmware automagically detect wifi or 4G comms and act appropriately. But it’s do-able I think if enough time is available for the software engineering and testing.

I did this already for adding the I2C mux board and eventually got it working. So this is a similar task.

@oscgonfer @victor @bryn.parrott

I am busy putting a dossier together as I mentioned so sky is the limit :stuck_out_tongue: I already had a quote for simcards that could carry the data for us - it would be around 4€ per sensor per month.

By the way any idea as to what is the data usage of the sensor per a time period? I assume with 100mb I will have more than enough.

How valuable would you deem having something like a port in the data board to connect to a SIM900 chip via the ESP, for instance

Very valuable!!!

But to clarify. At this point there is no possibility of extending the existing hardware with module that would allow for some gsm connectivity? I mean when you’re out there you need other connectivity types than Wi-Fi.

Sidenote LoRaWan is also interesting as it is operational in our location

1 Like

Even more interesting is this LoRaWan module:

Hi @bron,

Sorry for not responding. Data usage is responded here (just for reference for other readers).

But to clarify. At this point there is no possibility of extending the existing hardware with module that would allow for some gsm connectivity? I mean when you’re out there you need other connectivity types than Wi-Fi.

We are looking into this. Being totally strict, the only option to do so is to use the current auxiliary port and modify fhe firmware to send data to an external module via I2C (or other communication protocol really, as the auxiliary port is not strictly I2C, and can be mapped to other functions). This, however, would involve some knowledge of embedded programming and to understand the way the firmware works. Not wanting to discourage this route, but it would take some time and we are really very available for full support at the moment as we are busy with the following paragraph.

Since right now we are facing still issues with manufacturing, we are considering a hardware redesign. This new board, as @bryn.parrott suggests that would expose, as said above, some pins from the WiFi module (whichever we end up choosing) and, in that way, use it as a bridge to another communications module. This, however, would only be possible after we have new hardware ready.

Now, for this to be a standalone solution in itself, we still want to keep the wifi module in the board. The cost increase is not that high, but we don’t think it makes sense to remove it or make it swappable, but more to be a bridge to any other thing, that way, at least, you always have WiFi (remember that the kit is also used by people that are not so tech savvy as you are).

Sure the wi-fi has to stay as default. Extensibility with two designated modules (gsm, lorawan) albeit external, commercial products is an option. It should just be available for those who need it. A kind of half-integration.

1 Like

Owkay so I have a willing provider who can give us access to the following bands:
image

Now it’s just the hardware and software :stuck_out_tongue:

Here is an alternative.:

(Courtesy of Google)