LTE NB-IoT Shield for Arduino

This open-source, low-power LTE shield uses cutting-edge CAT-M technology and also integrates GNSS location capabilities!

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This open-source LTE shield uses SIMCOM's SIM7000-series modules with the latest LTE CAT-M technology to allow Arduino users to painlessly connect their low-power IoT devices with the next-generation cellular technology! NB-IoT is also available for many countries (but sadly not in the USA yet) simply by swapping out to a different SIM7000 module version. Luckily SIMCOM made it super easy to integrate this module because most of the AT commands are identical to previous version, and Adafruit has a wonderful library for their FONA 2G and 3G products. Check it out and help make this happen! You can view the latest code and design files here on my Github page: Note: The hardware works great but software is still under development! I plan on launching an Indiegogo campaign when I get a fully-working prototype, so stay tuned for updates!


With the emergence of low-power IoT devices with cellular connectivity and the phase-out of 2G (with only T-mobile supporting 2G/GSM until 2020), everything is moving toward LTE and this has left many people scrambling to find better solutions. However, this has also left many hobbyists facepalming with legacy 2G technology like the SIM800-series modules from SIMCOM. Although these 2G and 3G modules are a great starting point, it's time to move forward and SIMCOM recently announced their new SIM7000A LTE CAT-M module at a developer's conference. How exciting!   :)

The amazing part of all of this is that SIMCOM made it extremely easy to migrate from their 2G and 3G modules to this new module! The SIM7000-series use many of the same AT commands which minimizes the software development by miles! Also, Adafruit already has a wonderful FONA library on Github that can be used to introduce this new SIM7000 into the party!

What is LTE CAT-M?

LTE CAT-M1 is considered the second-generation LTE technology and is lower-power and more suitable for IoT devices. NarrowBand IoT (NB-IoT) or "CAT-M2" technology is a Low-Power Wide Area Network (LPWAN) technology specifically designed for low-power IoT devices. It is a relatively new technology that is, unfortunately, not yet available in the US, although T-Mobile has announced that they plan on delivering nation-wide (USA) NB-IoT coverage in 2018.

For IoT devices using radio technology (RF) there are several things to keep in mind:

  • Power consumption
  • Bandwidth
  • Range
  • Packet size (send lots of data)
  • Cost

Each of these have tradeoffs (and I won't really explain them all); for example, large bandwidth allows devices to send lots of data (like your phone, which can stream YouTube!) but this also means it's very power-hungry. Increasing the range (the "area" of the network) also increase power consumption. In the case of NB-IoT, cutting down the bandwidth means that you won't be able to send much data, but for IoT devices shooting morsels of data to the cloud this is perfect! Hence, "narrow"-band technology, ideal for low-power devices with little amounts of data but still with long range (wide area)!

The LTE Shield for Arduino

The LTE shield that I've designed uses the SIM7000-series to enable users to have extremely low-power LTE CAT-M technology and GNSS at the tip of their fingers! The shield also sports a MCP9808 I2C temperature sensor, great for at least measuring something and sending it via LTE! Currently I am using the SIM7000A (the CAT-M1 module) because in the US we poor souls don't have NB-IoT yet, unlike our European counterparts. However, for those in other places of the world with NB-IoT it's as easy as swapping out the SIM7000A with other versions like the SIM7000ESIM7000C, and SIM7000E-N modules.

Since I'm a huge fan of open-source (as you can see from my Reflowduino project) I've made this project completely open-source as well, with special thanks to Adafruit for their FONA library! (And if they'd allow it, I'd call this the "FONA LTE" but I'm not making that official due to copyright purposes lol).

Goals for this Project

I'd love to have this open-source design fully-integrated to the hobbyist market for Arduino users all around the world! I believe this is where the future is for cellular communication and getting this into the hands of users all around the globe will help to catalyze interest in this new technology. In order to do that I'll be launching an Indiegogo campaign on Feb 1st so stay tuned!

Meanwhile I've put some starter units available for sale here on my website!

Portable Network Graphics (PNG) - 232.56 kB - 01/09/2018 at 14:17


sch - 766.99 kB - 01/09/2018 at 14:17


brd - 151.63 kB - 01/09/2018 at 14:17


  • 1 × LTE Shield Kit I plan on selling it on my website and it will come with headers and the proper LTE/GNSS antennae:
  • 1 × Arduino This could be an UNO, Mega, Leonardo, etc.
  • 1 × SIM Card I personally used the Hologram Developer SIM card for testing!

  • Logic Level Shifter Voltage Feature

    Timothy Woo21 hours ago 0 comments

    Hey guys!

    On the beta units (which are completely sold out) I overlooked adding the ability to easily change the logic voltage of the level translator. This has been updated and the user will be able to supply VCC and GND of the logic voltage by simply cutting a trace on the bottom of the board and bridging the other side of a solder jumper.

    The files on Github have been updated to reflect these and some other minor changes.

    As a reminder the Indiegogo campaign is coming up very soon!



  • Design Files Released!

    Timothy Woo01/09/2018 at 14:12 0 comments

    Hey guys!

    I was originally going to release the files at the start of my Indiegogo campaign on Feb 1st but someone sent me a request to release the files for a university project and I'm all about learning so I obliged  :)

    You can find the design files here on Github as well as all the supporting documentation and step-by-step wiki.

    Anyway, there are tons of people out there who are eyeing this project so please support it before all the clones start hitting the market! It would mean a lot to a 20-yr-old just entering the open-source electronics industry!   <3



  • WUUT... OSH Park Jelly Beans???

    Timothy Woo01/09/2018 at 02:45 0 comments

    I was pleasantly surprised today when I opened a seemingly normal OSH Park package in the mail. Apparently OSH Park is equipping their patrons with the best bargaining tool there is -- jelly beans. Not only have my circuit board designs gone mad, but circuit board fabrication has reached apocalyptic proportions! Omnomnomnom...

    Stay tuned for my Indiegogo campaign which launches on Feb 1st!

  • LTE Projects for New Year!

    Timothy Woo01/02/2018 at 15:28 0 comments

    Hey guys, Happy New Year!

    I'm excited about the Indiegogo campaign for this shield which is launching on Feb 1st so be sure to sign up on the pre-launch page! This campaign will help me raise funds for practical things so I can scale the production of these boards and sell them to different parts of the world. Also be on the lookout for early-bird units! They'll be on Indiegogo for a discounted $99 USD + shipping for SIM7000A, C, and E versions (limited quantities!).

    My plans right after this SIM7000 shield is to test a new high-speed LTE shield with audio support that I've already designed. Maybe watching Simon's cat on an Arduino LCD display via LTE might not be that far from our reach! I'll have more info about this when I get it built, tested, and ready to roll!

    As always, please share this project on social media and check here for the latest updates on the project! Your support will help me bring LTE to Arduino users all around the world!

    ~ Tim

  • GPS Tracker Tutorials!

    Timothy Woo12/31/2017 at 19:36 0 comments

  • LTE Shields Galore!

    Timothy Woo12/28/2017 at 00:35 0 comments

    Hey guys, check out my inventory of v4 shields, hand-crafted by me, proudly baked in the USA! These units are primarily for early-bird orders on Indiegogo but I'll take any orders before that too! This version is compatible with Arduino Uno, Mega, and Leonardo. All boards are fully-tested and ship in anti-static bags with dual LTE/GPS antenna and stacking female headers.


    And, of course, all open-source!

  • Early-Bird Boards Arrive!

    Timothy Woo12/26/2017 at 18:17 0 comments

    The version 4 boards have arrived and I can now populate them to get them ready for the Indiegogo campaign for early-bird orders! Yippee!

  • Adding Audio Support!!!

    Timothy Woo12/25/2017 at 17:24 0 comments

    Hey guys,

    Great news! I'll be adding audio support for the next version (v5) that will enable you to easily connect a microphone and speaker to the shield via a four-pin header so you can call your pet while away from home?!?! And all that stuff within the same shield dimensions!

    Unfortunately adding audio support meant taking away the extra I2C header that I had included previously, but I'm not sure how many people would be using the extra header anyway, so I don't feel all that bad.  :)

  • Announcing the LTE/NB-IoT Shield Launch Day!

    Timothy Woo12/21/2017 at 15:21 0 comments

    Hey guys, I'm excited to announce that this shield will be going live on Indiegogo on Feb 1st of the new year so mark your calendars! You can check out the pre-campaign page here and be sure to share it with your friends!

    Early-bird orders will ship out immediately but I will have limited supplies on a first-come-first-served basis. The price for any version of the shield will be $99 (USD).

    Looking forward to the new year and stay warm!

    ~ Tim

  • Tutorial + Campaign Preview

    Timothy Woo12/18/2017 at 16:23 0 comments

    Hey guys, quick update here!

    I just posted a demo tutorial for the LTE shield on my humble YouTube channel which you can find here. I'm also prepping for a crowdfunding campaign hopefully sometime next month and you can visit the campaign preview here. Early-bird orders get their units shipped out immediately because I'll have units ready to ship before the campaign starts!

    Wishing you all a wonderful holiday season!

    ~ Tim

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Zeqing wrote 5 days ago point

For previous SIM900, the peak currently can be 1.2A when power up~~ which may leads to Power  down for the whole system, i designed a special power-lack power circuit to avoid that. so maybe the SIM700 do not have the alike problem ?

  Are you sure? yes | no

Timothy Woo wrote 4 days ago point

No, fortunately it does not have this issue.  :)

  Are you sure? yes | no

Craig wrote 11/20/2017 at 15:35 point

Any idea what power consumption is like? Or what it would look like in a sleep/standby mode? I have an application in mind where I'd like to maximize battery life for several months: sleep for a week, wake up, transmit, sleep for a week, etc..

  Are you sure? yes | no

Timothy Woo wrote 11/20/2017 at 15:45 point

You can turn the device completely off by using "AT+CPOWD=1" or using the PWRKEY pin which would practically draw nothing at all because it actually kills the power to the SIM7000 altogether. If you take this route you would only have to worry about the sleep current of the microcontroller itself. However, you could also put the SIM7000 into a sleep mode (similar to the ESP8266 deep sleep) where it draws only 9uA and you can have it wake up via its RTC. During LTE transmission it draws around 115mA compared to the much higher 325mA+ for 2G/GSM. You can refer to the SIM7000 Hardware Design document, section 5.4 "Current Consumption".

You can view a recent tutorial I posted here: and check out my Github page for more documentation (like the SIM7000 Hardware Design document):

  Are you sure? yes | no

Timothy Woo wrote 11/24/2017 at 03:40 point

Correction: Actually it seems like the SIM7000 draws 7uA when powered off, according to the SIM7000 spec overview. However, with the latest version (v3) of the LTE shield you can cut off power to the regulator to minimize the current consumption even more.

  Are you sure? yes | no

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