Development boards with 4G LTE are still quite expensive, at least compared to 2G or 3G solutions, with for example Wio LTE GPS Tracker board selling for around $100. So when I saw Sixfab introducing a 3G/4G shield for Raspberry Pi 3 for just $31.20 (pre-orders), I first thought it was an incredible deal.
But I soon realized I missed the “base” word in the name, as the shield just includes the SIM card slot, and mPCIe connector where you can connect Quectel’s UC20-G Mini PCle 3G module or EC25 Mini PCle 4G/LTE Module which adds respectively $59 or $89 to the price. That’s still an interesting HAT board, so let’s have a look.
Raspberry Pi 3G-4G/LTE Base Shield V2 specifications:
- Clip-in Mini PCIe socket for:
- 4G/LTE Module (Quectel EC25) up to 150Mbps downlink and 50Mbps uplink data rates, GPS/GLONASS
- 3G Module (Quectel UC20) up to 14.4Mbps downlink and 5.76Mbps uplink, GPS/GLONASS
- Micro SIM card socket
- USB – 1x micro USB port
- Compatible with 40-pin Raspberry Pi header
- Power Supply – 5V via micro USB port or external 5V source
- Dimensions – 65 x 55 mm
The new version improves on the first model for the shield by reducing the area by 25%, removing the need for screws for the cellular module, using a micro SIM card socket on the top of the board, a more efficient power circuit, and removing the DC barrel jack.
While the board is mostly designed to be used with Raspberry Pi 3 board, it can also be used standalone with your computer, laptop, or another development board over the micro USB port. A blog post explains how to make a PPP Internet connection with the shield connected to RPi 3, and you can get supports in their forums.
Thanks to Nanik for the tip.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Please replace the picture above with the one showing how ugly and impractical this really is: http://sixfab.com/wp-content/uploads/2017/10/base_shield_v2_1.png
Also the silkscreening is misleading as usual since this is just an USB modem using mPCIe slot. That’s why the USB connection is needed and why you can replace the whole combo with an 3G/4G USB dongle in the first place.
Or get one of these if you want to use a mPCIe modem: http://www.ebay.ca/itm/Mini-PCI-E-mSATA-to-USB-3-0-External-SSD-PCBA-Conveter-Adapter-Card-/252053388785?hash=item3aaf8d7df1:g:LVIAAOSwgQ9Vya6v
@RoganDawes
No, your eBay link shows something totally different (USB3 attached SATA controller to be used with mSATA SSDs) while the above is just a boring PCB getting power and USB data lines from a Micro USB port, doing some voltage regulation and then providing the USB data lines on pins 36 and 38 of the mPCIe connector.
With this thing from your eBay link none of the WWAN modems would work since they need USB2 and not SATA.
@tkaiser
I can see the mPCIe connector exposes both UART and USB, so it could be that USB is optional. UART would have a slower bitrate though.
The schematics for the first model can be found on Github: https://github.com/sixfab/rpiShields/tree/master/hardware_design_files/schematics/3g_4g_lte
Now I always consider mPCIe to just be a connector, unrelated to PCIe.
i have this one
https://www.aliexpress.com/item/Mini-PCIe-To-USB-Adapter-for-3G-4G-WWAN-and-WiFi-USB-Type-Card-Mini-PCI/32791282970.html
10$ and work perfectly on raspberry 😀
@cnxsoft
So I’ve just talked with somebody who is designing something similar to the Sixfab board, except the Quectel module is soldered. Both USB and UART can be used but…:
@Youcef
Good find. Did you put it in a case with RPi 3 too?
@cnxsoft
I don’t think the schematics for first board variant help since different. If they advertise the 2nd variant being useable with any host by connecting it to the Micro USB port then this adapter now might not be using the UART on the RPi GPIO header any more but will behave like any 3G/4G USB dongle: you attach the thing and /dev/ttyUSB0, /dev/ttyUSB1 and /dev/ttyUSB2 appear, no real serial port is used and all communications is going over the single USB2 connection. All these WWAN ‘mPCIe’ cards only use the USB data lines and the different voltages available on the connector.
Such WWAN HATs above would be more interesting for boards that have USB data lines on a GPIO header like Orange Pi Zero or the smaller NanoPi. But I doubt there is a market so the obvious tinkerer solution to get something with minimal space requirements is adding such an USB adapter like @Youcef showed with USB jack desoldered and replaced with 4 really short jumper wires connected to 5V/GND/USB pins of an el cheapo Orange or NanoPi.
@cnxsoft
Maybe worth an own blog post to educate users about this mPCIe connector mess? The answer on https://electronics.stackexchange.com/questions/26961/ might be a good starting point though the link to specreport.com is broken now (links to an ad network now, maybe malware too).
Why not just use an USB modem?
@TC
The above product does only work with USB modems 😉
@cnx : “Development boards with 4G LTE are still quite expensive”
Yes, and often also have poor specs compared with what we see on smartphones. I am still waiting for a cost-effective “smartphone on a module/board” (that would natively include large CPU, large RAM, large eMMC, wifi… like in a smartphone, and also have the modem and GNSS). I don’t understand why those dev boards from MTK or Qualcomm never include/activate the modem. I would love to get the characteristics of a Oneplus 5 mainboard (SD835, 8G RAM, eMMC, modem/sim and GNSS, battery connector…) on a RPi/PC104/pandaboard form-factor with all I/O exposed and for less than 100$ (I don’t know how much Qualcomm charges for SD835 or how much MTK charges for Helio X30 but even if they charge 50$, if there is no touchscreen or gorilla glass, no casing, no camera, more spacing for the components and heat dissipation, etc. I guess it should be feasible). Maybe we will finally see soon a new era of non-smartphone boards considering Qualcomm/Microsoft agreement ?
This seems very similar, just more Pi-focused, to Harald Weltes Design:
https://osmocom.org/projects/mpcie-breakout/wiki
You never see cheap cellular dev hardware because of PATENTS, PATENTS, PATENTS, PATENTS! A typical cell modem can be required to pay up to $30 per modem in royalties. It is crazy that the patent situation is so bad. But that’s what you get when there are over 250,000 patents on cell phones.
Just stick with USB cell modems and stay out of this mess.
Also, don’t be misled by a $6 cell modem chip. The chip is $6, but then you will have to pay up to $30 to license the firmware that runs on it. There is no open source, low-level cell software. This is not because people are against open sourcing it, it is because the patent holders stop it.
The price of 2G/3G is falling a lot now, but that is because the 2G/3G patents are expiring. By some random coincidence, the developed world is in the process of turning off 2G/3G and moving to patent coated LTE.
Seems like a USB modem makes way more sense.
For 2G/3G can just get https://www.amazon.com/dp/B00ULLGNRM or https://hologram.io/nova/
and Hologram is coming out with a Cat-M1 version soon
Sounds weird that the 4G modem offers 150/50Mbps while RPis own ethernet is only 100/100. So you could basically download data faster from other continents than from a nearby PC?
HI ! I’ve some issue using the EC25-E. I never get local ip addresse
Here my logs: https://pastebin.com/GbX33rwD
What can be wrong ? My configuration work well with sim7200
Sixfab products are garbage!!!!! I spent the best part of two months with these guys trying to get their shields to work in Australia. I tried multiple shields, antennas, SIM cards, locations. None of them worked. Their product was the single point of failure for my companies project. Stay well clearl
This product is crap and their support is even worse.I spent the good part of two months on my own time, at my own expense working with Saeed at Sixfab trying to get this POS to work and solve their issues with their CRAPTEL shitty hardware. I incurred out of pocket expenses that were never reimbursed. I tried multiple boards, multiple locations, drove their shit all over town as they thought it was a signal issue, issued a million AT commands and sent them all the logs. We tried multiple antennas, different cell phone carriers. As a software developer with well over 25 years of experience I would say stay well clear of this rubbish!