The 7€ LTE module FS800E: A review (and guide-ish thing)

This article is part of a series on the cheapest LTE modules of AliExpress. Please Donate to keep this series alive.

The appeal

The FS800E is extremely cheap. Not just one of the cheapest, it is THE cheapest LTE modules I have ever seen. It clocks in at 3.71€ for the core itself, and 6.73€ for a pre-assembled board WITH external antenna.

I bought the board because I do not want to deal with SMD soldering such a small thing.

Specs

Compatibility

I live in germany, and tested out two SIMs so far: One from the Telekom (D1 network), and one from 1und1 (EPlus network). Most FDD bands are deployed in europe (and one TDD band: B38). In germany itself however, only the B1, B3, and B8 bands are deployed (plus others this module can't access anyway). They're deployed by ALL carriers, but with different coverages.

The D1 SIM had great reception as the D1 network has particularly good coverage. It seems the EPlus one was not so lucky. I was unable to get any reception at all with it, even though the network is supposed to support the B1, B3, and B8 bands, so this is probably just an issue in my area.

Getting it to talk

However, getting it to actually connect to the internet is a bit unintuitive at first, and no documentation was provided (but here is a link to that which I ended up getting). It took me a few days and some conversations with the seller to figure out how to get it to respond to commands and set things up, but I am now sharing this process publicly, as a sort of third party documentation (XD):

There is however one more thing that greatly tripped me up: All commands must be sent VERY quickly and cannot be typed by hand over minicom or something like it. The module expects a command to be received extremely quickly and otherwise won't run it.

Problems arise

So far, this has all worked relatively well after figuring out the documentation and serial quirks, but there is also an issue with functionality: The module just doesn't connect! I'm serious. It logs into the LTE network, even getting cell tower information, but it does not connect to the internet. AT+CIP (command to get current ip) always returns 0.0.0.0. The actual internet connection just doesn't happen. Here's what that looks like: FS800E not registering on internet.

It is entirely possible that I simply received a defective unit, because if I remember correctly, it emitted a smell when I first tried to use it. Not sure if that was from outside though, as I had the windows open and the smell was really faint.
Either way, I have a replacement on the way to test a new unit with all the information I have right now.

I am in conversation with the seller to get this resolved, as it seems the module simply fails to connect to the correct APN or something like that. But for now, I can't really recommend it. It's extremely close to working, but fails me in the last minute.

I recommend you check back on this article soon, because I might be able to get this resolved.

Conclusion

So, considering this, I can't recommend it as of now. I encourage you to buy one to test it yourself - because for that price, you can't go that wrong. Maybe this is just an issue here in Germany, maybe not. Maybe my unit is defective (which is actually kind of likely) It is not defective, I have checked another unit.

One thing I can say for certain: It is not fake. What I received is definitely an LTE module. It shows signal strength that actually varies with different environments, and it can display cell tower information. There's also people online who have apparently been able to get it to work, but I only found those in chinese forums, so it might also be a location-based issue.

A firmware update would fix the module, but so far, none such is available.