Reddit mentions of Unlocked Modem USB 4G LTE Huawei E397u-53 Worldwide Hotspot Service Required Only T-mobile in US

$222 USD?? Call me crazy, but that puts this hat well out of DIY territory let alone any budget IoT project which the Pi is used for in the first place.

EDIT: I’ve got to be missing something. TR is saying this is affordable compared to other options. Besides being a hat, how would this be different from a [4G USB dongle](Unlocked Modem USB 4G LTE Huawei E397u-53 Worldwide Hotspot Service Required Only T-mobile in US https://www.amazon.com/dp/B01M0JY15V/ref=cm_sw_r_cp_api_zAE0BbTXZT1ZX)?

By 4G dongle I meant a USB 4G modem, like this one.

You just put a SIM card on it with a decent data plan and plug it into any USB port in your PC.

A MiFi is just like a small wifi router that uses a 4G SIM card for connectivity instead of a fixed line. But this may not be a valid solution for you as I guess it will still require permanent power, just like a regular DSL/fibre router... so it might be exposed to current peaks. Maybe it can use a regular USB port in your laptop as power source? (haven't used any recent ones)

It would be very convenient, because you can then provide connectivity to all your devices and not just your PC.

Example.

If you mean wifi hotspot, mobile carriers sell those. You could also just use your phone as a hotspot. If you want a device for a single connection that gets mobile internet on the go you can get what I got. I got an extra data sim line free from Tmobile a couple months ago from one of their promotions. I bought one of these, popped in my sim, and connected to my Surface Pro 4. I don't have to use my phone's hotspot anymore.

https://www.amazon.com/Unlocked-Huawei-E397u-53-Worldwide-Desbloqueado/dp/B01M0JY15V/ref=pd_sim_107_2?_encoding=UTF8&pd_rd_i=B01M0JY15V&pd_rd_r=VBYECTQP96W5X8G6BN5K&pd_rd_w=RlljH&pd_rd_wg=F1L0S&psc=1&refRID=VBYECTQP96W5X8G6BN5K

The one I was looking at is http://www.ebay.com/itm/162200904842?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

What I ended up ordering is https://www.amazon.com/gp/product/B01M0JY15V/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I'll post back here when I get mine and get it working, but take a look at the amazon reviews, there has been some success with using this adapter with Linux. Hopefully it's pretty reliable while using a Fi data sim.

A router won't add much in terms of power draw, a few watts when it's in use and you can turn it off whenever you're not using it. Something like this is fairly small and can be easily mounted to a wall or underneath a shelf with velcro.

In terms of 'turn off wan' that just means turning off the 'wide area network' or basically turning off the routers internet capabilities. It's likely not necessary, but a good measure if you want to use it for local devices only.

I don't believe you could use a phone or tablet to provide internet to the rest of the devices on the network. You'd likely need something more like this to distribute a 4g connection to several devices. There is a lot more to it in terms of network carrier issues, device compatibility, etc. but it would certainly be possible if you wanted to go that route.

To simplify for your original question, it really wouldn't be necessary to add 4G access for this to work, but it would be an option if you wanted to add internet access to the setup later on. I usually start with the basics but plan for the inevitable additions later.

if there's a "no thanks" link, it's less shameful. here's a travel router with a usb gsm module that could work with a custom captive portal

I found this one from Huawei works for the data sim. Also, pick up an adaptor.
https://www.amazon.com/gp/product/B01M0JY15V?ref%5F=oh%5Faui%5Fdetailpage%5Fo04%5Fs00&redirect=true&psc=1&pldnSite=1
https://www.amazon.com/gp/product/B00R25GJJW?ref%5F=oh%5Faui%5Fdetailpage%5Fo03%5Fs00&redirect=true&psc=1&pldnSite=1

As a suggestion, I think you might want to get something like this (I think this one is only T-mobile in US) which could plug in to a Pi Zero (with a connector).

https://www.amazon.com/Unlocked-Huawei-E397u-53-Worldwide-Required/dp/B01M0JY15V/ref=pd_sbs_147_3?_encoding=UTF8&pd_rd_i=B01M0JY15V&pd_rd_r=67GRJCEV19N8CXCZCNEZ&pd_rd_w=fMpcp&pd_rd_wg=qCVYQ&psc=1&refRID=67GRJCEV19N8CXCZCNEZ

You would need Phone Sim card I think and Zero SD card and a weatherproof case.

You would then need a motor driver board and a motor (or solenoid).
You would probably want some sort of detector to detect "gate closed".

You would have to have power out to the gate.

I think you could probably make one cheaper, but it depends on how much you value your own time.

The GPRS usb dongles has given me a few ideas on other projects, so thanks.

this is what I ordered. No band 12 but is that really a huge deal?

https://www.amazon.com/dp/B01M0JY15V/ref=pe_1098610_137716200_cm_rv_eml_rv0_dp

I don't need a crazy fast connection, this is for an Android head unit that needs data to run maps and maybe stream a little low quality music on Play.

Or will I need something like this maybe

https://www.amazon.com/Unlocked-Huawei-E397u-53-Worldwide-Required/dp/B01M0JY15V/ref=sr_1_2?keywords=usb+lte+modem+tmobile&qid=1549642597&sr=8-2


But again question is will you need Phone Line SIM or Data/Hotspot SIM?

Saw this on eBay while looking for a good LTE stick, I looked it up on Amazon and it supports 700mhz LTE, but is it B12 and T-Mobile compatible?

Here is the Amazon page: https://www.amazon.com/Unlocked-Huawei-E397u-53-Worldwide-Required/dp/B01M0JY15V