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Show HN: Hacking a $20 4G wireless hotspot into a texting devicebkovac.github.io
210 points•bobili1234•15 days ago•37 comments•
#hotspot#wireless#hacking#texting#device#wireless hotspot#texting device

37 comments

notpushkin15 days ago
This is really nice! It so happens that I’ve just bought a $10 4G dongle [1], guess I’ll have to check what’s inside now :-)

[1]: like this: https://img.joomcdn.net/ea91b4418997d83d802339fad0bbcf878b9d...

---

Aside, but it appears some MSM8916-based dongles run Android UI despite having no display: https://github.com/u0d7i/uz801#screenshots

kotaKat15 days ago
I did some funny software porting on one of those dongles. At one point, I had it connected to a battery pack for power, joined onto my home WiFi for LAN/WAN access... and had the stick running the Open5GS cellular core stack, allowing my CBRS LTE base station to serve users on an in-home private LTE network by connecting to the cellstick over WiFi for management. (No, the stick's own cellular modem wasn't being used here at all. Just scavenged compute for the tiniest LTE core!)

So... so cursed.

djfergus15 days ago
Postmarketos works well on those and they have lots of info and links. [1]

My biggest tip is to carefully back up every partition of the original firmware - there are many many seemingly identical variants and if you hose your particular baseband components you will lose your cellular functionality.

[1] https://wiki.postmarketos.org/wiki/Zhihe_series_LTE_dongles_...

untitaker_15 days ago
it's most likely UZ801 (mentioned in the article)
notpushkin14 days ago
It’s a weird one!

  [ro.build.description]: [msm8916_32_512-userdebug 4.4.4 KTU84P eng.huanghonghuan.20250226 test-keys]
  [ro.build.sw.custom.version]: [UFI003S_V03_ZX_DD_250226]
walrus0115 days ago
Based on the work the person has done, if they wanted to make something with an exceedingly long battery life, and the battery setup there already seems to be basically a 1S li ion, they could graft in a back side battery holder for two high quality 18650 cells in parallel. It would probably last weeks.
iamnothere15 days ago
A 10000mAh pouch battery would take up less room and provide more battery life. They are almost as cheap as 18650s too.
walrus0115 days ago
The neat thing about 18650s though is that you can put a battery door on it and make them swappable, if a person used a holder that can accommodate button top protected 18650 cells. The same cells can also be shared by a bunch of good quality flashlights and headlamps. I have several extremely useful headlamps from "sofirn" that take my choice of cell and have a built in USB-C charging port and charge circuitry protected behing a gasket and twist-open ip67 sealed cap. The pouch battery would be better as an integrated all in one product but also makes the thing a bit less modular.
jsisto15 days ago
How is a 10000mAh pouch more energy dense than an 18650?
harhargange15 days ago
I often ditch my phone and carry my hotspot device for my internet. The only drawback is that for viewing my texts and OTPs i end up putting the sim in my phone or opening up the web interface on my laptop. This seems to work very well as a dumbphone per se.
newhotelowner15 days ago
How do you check sms/OTP/text using web interface on your laptop?
notpushkin15 days ago
This probably depends on your particular dongle model. Back in 3G era, some carriers offered USB modems with SMS locked out in the firmware, but you could flash a firmware from a different operator (also install their variant of software, the only difference being the added SMS tab and a different skin) and then you can text and even use USSD! (No calls, though.)
knowaveragejoe15 days ago
https://messages.google.com/web/ is one way I'm aware of, I'm sure there's others depending on the messages app used.
harhargange15 days ago
yeah my vendor's dongle has this specific feature. A light also turns ON on the modem when SMS is received.
blobbers15 days ago
If you move to an Apple set up, the phone can act as a hotspot and there is no need to take out your sim. Also... you have a physical sim card? I thought those became obsolete.
toast015 days ago
Physical sims are as obsolete as 3.5mm headphones. They both continue to work and have different tradeoffs than 'modern' alternatives and you have a different selection of devices to work with.
xx_ns15 days ago
This is a really cool project! A mini cyberdeck that doesn't seem too impractical to use. Repurposing the Clicks keyboard is a genius idea.
msm891615 days ago
OpenStick is super old though, there are Linux and OpenWRT builders that track the upstream kernel, check hkfuertes and others.
ACCount3915 days ago
Oh, if it isn't the MSM8916 himself! Fancy seeing you out there in the wild - posting on HN no less!

Is there a guide for cheap MSM8916 platforms you would recommend? There is a hkfuertes repo, but the one I found is archived. Not to say it doesn't work, but that doesn't instill much confidence.

Matsta15 days ago
Not tried but seems like a fairly recent Arabian build (last release was June) https://github.com/Crychic-Band/msm8916-armbian

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