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Review: New 3G and Cat-M1 Cellular Hardware from Hologram
Friday, 06 October 2017 10:01

In July we reported on the launch of the Hologram developer program that offered a free SIM card and a small amount of monthly cellular data for those who wanted to build connectivity into their prototypes. Today, Hologram has launched some new hardware to go along with that program.

Nova is a cellular modem in a USB thumb drive form factor. It ships in a little box with a PCB that hosts the u-blox cellular module, two different antennas, a plastic enclosure, and a SIM card. The product is aimed at those building connected devices around single-board computers, making it easy to plug Nova in and get connected quickly.

This device that Hologram sent me is a 3G modem. They have something like 1,000 of them available to ship starting today, but what I find really exciting is that there is another flavor of Nova that looks the same but hosts a Cat-M1 version of the u-blox module. This is a Low Power Wide Area Network technology built on the LTE network. We’ve seen 2G and 3G modems available for some time now, but if go that route you’re building a product around a network which has an end-of-life concern.

Cat-M1 will be around for much longer and it is designed to be low power and utilizes a narrower bandwidth for less radio-on time. I asked Hologram for some power comparison estimates between the two technologies:

AVERAGE current consumption comparisons:

Cat-M1: as low as 100 mA while transmitting and never more than 190 mA
Equivalent 3G: as high as 680 mA while transmitting

PEAK current consumption comparisons (these are typically filtered through capacitors so the power supply doesn’t ever witness these values, and they are only momentary):

Cat-M1: Less than 490 mA
Equivalent 3G: As high as 1550 mA

This is an exciting development because we haven’t yet seen LTE radios available for devices — of course there are hotspots but those are certainly not optimized for low power or inclusion in a product. But if you know your ESP8266 WiFi specs you know that those figures above put Cat-M1 on a similar power budget and in the realm of battery-operated devices.

The Cat-M1 Nova can be ordered beginning today, should ship in limited quantities within weeks, with wider availability by the end of the year. If you can’t get one in the first wave, the 3G Nova is a direct stand-in from the software side of things.

I suspect we’ll see a lot of interest in Cat-M1 technology moving forward simply because of the the technology promises lower power and longer support. (I’m trying to avoid using the term IoT… oops, there it is.) For today, let’s take a look at the 3G version of the new hardware and the service that supports it.

Hands-on the 3G Version

Hologram sent me a review unit and I gave it a try. It is incredibly easy to get up and running and I think there’s a place for this in every hacking toolbox alongside other ubiquitous boards like the ESP8266 and tools like USB to Serial cables. That’s because, if you’re already running a single board computer with USB, the amount of time and effort you’d spend adding this to the mix is negligible.

I originally tested Nova with my computer — it runs Linux just like a Raspberry Pi so why complicate my tests? The Hologram software is trivial to install with a curl command. It wouldn’t connect to the cell network while my WiFi was enabled (more on this below) but once I turned WiFi off it worked great. Sending and receiving messages from the Hologram.io web-based dashboard was easy. You do need to set up the software in receive mode or it seems like you’ll miss incoming messages send from the dashboard. I grumble a bit about prefixing all commands with sudo but I suspect a bit of udev rule magic would get around this issue.

A Few Surprises While Testing

I encountered a few issues in testing. If you’re going to give this a try, plan for the following.

The one real showstopper that I had was when I reached for the single-board computers. On both a Raspberry Pi model B and the C.H.I.P. there were brownout issues. It takes a lot of power to transmit on 3G (see the quoted power earlier in this article). On a USB power supply rated at 1.2 A the dongle could receive just fine, but the modem would seem to reset when trying to transmit. I also tested Nova on the C.H.I.P. running from USB power and it would shut down the instant I plugged in the NOVA. I had none of these problems from a laptop so the answer is to get a better supply or use a powered USB hub. (I think Hologram recommends a 2.5 A supply for the Raspberry Pi.)

In retrospect the second surprise is sort of a facepalm moment for me. I ate up my developer program data allotment for the month out without realizing I was doing anything. When Nova enumerates it immediately takes over the PPP service for the system. This is why I had to disable my WiFi to use it. The thing is, Hologram provides an Internet connection to whatever you connect so I was using data by trying to load webpages over WiFi. Oops.

I inquired about this and it is likely that a bit of Linux Fu (or possible future work on what is an alpha SDK) will offer a workaround. The more important thing to realize is that this is a feature and not a bug. You don’t have to use the Hologram dashboard for communications. If you have a (cough) IoT prototype that needs a path to the Internet, just plug it in and issue the connect command and you’re off to the races.

To both of these issues I say it’s dev hardware and dealing working with these constraints in mind (or solving them for yourself) is reasonable.

Hologram Isn’t a Hardware Company

I think the engineers at Hologram straight-up told me at one point that Hologram isn’t a hardware company. Their focus is on a cell network that covers the globe and the coordination tools necessary to deploy a hardware network on it. Their approach is that of an MVNO. In the same way that Google Fi enables you to take a single phone and SIM card just about anywhere in the world and have it just work, Hologram wants your single hardware modem and SIM to do the same.

SIM Card punches out to 3 different form factors

Is this the solution that cell-connected hardware developers have been waiting for? Imagine you are developing a product to track shipping pallets. It wakes up and squawks some logged data to the cell network from time to time. Wherever it is, your network agreement is already solved and not locked to a single network provider.

Hologram does boast coverage throughout the world. There isn’t yet a coverage map that you can just search but when I asked Hologram mentioned they’re happy to work closely with developers and can supply specific information for any request. They have also made available a nice web interface that lets you work with individual nodes in your network in a lot of different ways. In other words, if you need a vast network of cell-connected devices, Hologram is worth testing.

It used to be really hard to connect a device to WiFi and now that’s become unbelievably easy. Cellular is the next wireless frontier for the electronics industry. The 3G Nova makes it easy to give this a try yourself. Its USB form factor makes it a development tool on the path to a manufactureable device. But Hologram doesn’t care if you use Nova, or bring your own hardware. This laissez faire approach is very welcome coming after decades of telco death-grips regarding what hardware can be attached to their networks.


Editor’s Note: Hologram is a sponsor of the 2017 Hackaday Superconference. This review is not a part of that sponsorship. Hackaday loves getting a first look at new hardware and we respect press embargoes. If you have new hardware coming out and want to give us an early look, please This e-mail address is being protected from spambots. You need JavaScript enabled to view it .


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