What are options for inexpensive 3G chips for use in small IoT device?

March 15, 2016 6:37 PM

2G networks are about to be discontinued and "upgraded" to 3G. I have a prototype of an IoT device that would work great with 2G because it periodically sends and receives very small amounts of data. But now I have to find 3G chips, which appear to be much more expensive. What are some 3G chips that I can use in my device that are reliable (FCC approved) but inexpensive? Are there wholesale sellers I can work with to find the right type of chip and pair it with mobile network providers?

I have built one-off models using particle's photon and electron, but they are way too expensive to sell at scale.

Thanks in advance!

posted by erikvan to Technology (13 answers total)

USB LTE modems are available for under $10, and you could use something like a Raspi Zero as your CPU which is also a USB host. That gets the cost down significantly. I don't know of anything close to that price that can use a microcontroller.
posted by miyabo at 6:40 PM on March 15, 2016

Response by poster: Under $10! Wow I've been out of the game for a while. Do you have any suggestions for sites/manufacturers to find something like that? Thanks!
posted by erikvan at 6:46 PM on March 15, 2016

If you want breakouts, something like the Adafruit FONA 3G ($80) or the Sparkfun MG2639 ($70) might be a place to start.

(Those have a more expensive sticker price, but they're not subsidized by the carrier. Look at TCO for your product. If the hardware is free but you have to commit to $10/mo. for two years...)
posted by sourcequench at 7:57 PM on March 15, 2016

I'm fairly confident that a $10 LTE modem is a loss leader from a carrier just to get you on an expensive data plan. But who knows, maybe you can buy them in quantity from a carrier if you plan to buy enough bandwidth to make it profitable for them.

Seconding FONA, they have some more affordable boards now that use the same SIM800L module. You'll need a carrier SIM card, which can be an additional $10 or so. While the module is FCC approved out of the box, it doesn't include an antenna or the cabling to get your antenna into a clear signal.

I guess your eventual goal is to find a distributor that carries modules like the SIM800L in quantity for your product, or get them right from Asia.
posted by JoeZydeco at 8:01 PM on March 15, 2016

There appear to be vendors selling SIM800L modules on Alibaba for < $10 a piece. Here’s one I picked at random.

The usual caveats apply to ordering stuff sight unseen from Alibaba of course :)
posted by pharm at 2:04 AM on March 16, 2016

NB. The SIM800l will *only* run from a max 4.4V source that can (briefly) supply 2A. IOW, it wants to be hooked up to a LiPo mobile phone battery. An ordinary 5V source will *not* work according to the comments I see around the net. (You can of course fiddle around with zener diodes and the like to create a sub 4.4V source from a 5V one.)

See, eg, the README.md from this github project.
posted by pharm at 2:13 AM on March 16, 2016

The SIM800 is advertised as a 2G device, so might not be what the OP wanted. 3G is still pricey.
posted by scruss at 7:39 AM on March 16, 2016

Drat, you’re right! Shame, it looks like a useful little piece of kit otherwise.
posted by pharm at 8:15 AM on March 16, 2016

The same company makes a variety of similar form factor 3g devices.

But they’ll be more expensive obviously.
posted by pharm at 8:30 AM on March 16, 2016

Response by poster: So it seems that there are 3G options (or even LTE), but they appear to be considerably more expensive than 2G or come with strings attached (like a monthly contract).
posted by erikvan at 11:41 AM on March 16, 2016

Response by poster: This is the particular solution SIM recommends. Not sure if it's more than I need, but it's definitely 3G.
posted by erikvan at 3:20 PM on March 16, 2016

http://nimbelink.com/ I have used their 2G products and been happy. More expensive than a FONA, but most of the modules are FCC and carrier approved.
posted by fbo at 5:11 PM on March 17, 2016

You might consider Particles upcoming Electron. It's 70$ and that includes a complete kit and three months of cell service. After that it's 3$ for 1MB of service a month, and there's no contract. Intro is available over at Arstechnica.
posted by zenon at 7:10 PM on March 18, 2016