Home > Broadcom BCMxxxx, Hardware > SixFab Launches Raspberry Pi 3G-4G/LTE Base Shield V2 for $31.20

SixFab Launches Raspberry Pi 3G-4G/LTE Base Shield V2 for $31.20

Orange Pi Development Boards

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 3 + 3G-4G/LTE Base Shield + Quectel EC25-E 4G Module

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.

  1. tkaiser
    October 20th, 2017 at 12:34 | #1

    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.

  2. RoganDawes
  3. tkaiser
    October 20th, 2017 at 13:52 | #3

    @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.

  4. October 20th, 2017 at 14:22 | #4

    @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.

  5. Youcef
    October 20th, 2017 at 14:47 | #5
  6. October 20th, 2017 at 15:03 | #6

    @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…:

    For USB it’s working like USB Modem.
    There are /dev/ttyUSBx for
    – USB Modem work like modem support all data and tcp/ip and also sending AT command
    – USB AT for sending AT command but not for data
    – USB NMEA for GNSS output

    You can use PPP connection via USB modem port.

    UART also supports AT commands and data at slower rate. Excludes PPP.

  7. October 20th, 2017 at 15:06 | #7

    @Youcef
    Good find. Did you put it in a case with RPi 3 too?

  8. tkaiser
    October 20th, 2017 at 15:32 | #8

    @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.

  9. tkaiser
    October 20th, 2017 at 16:06 | #9

    @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).

  10. TC
    October 20th, 2017 at 17:14 | #10

    Why not just use an USB modem?

  11. tkaiser
    October 20th, 2017 at 17:19 | #11

    @TC
    The above product does only work with USB modems 😉

  12. ade
    October 20th, 2017 at 19:05 | #12

    @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 ?

  13. linmob
    October 20th, 2017 at 20:14 | #13

    This seems very similar, just more Pi-focused, to Harald Weltes Design:

    https://osmocom.org/projects/mpcie-breakout/wiki

  14. Jon Smirl
    October 20th, 2017 at 20:25 | #14

    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.

  15. RB
    October 21st, 2017 at 01:20 | #15

    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

  16. Jerry
    October 21st, 2017 at 03:11 | #16

    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?

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