An Off-the-grid messaging system.

Similar projects worth following
A wearable ESP32 based hardware that can connected to a smartphone/PC and allows it to communicate with other device with similar hardware. Communication between the hardware and Smartphone/PC is via BLE. Sub-stations/Routers Could be introduced if needed.

The LoRaSleeve is a small piece of hardware that enables communication between devices connected to similar hardware. The LoRaSleeve is ESP32 based and has a small form factor. This allows for it to be hung around the neck or wrist. It simply connects to the device (PC / Smartphone) through BLE and serves as a portal for sending and receiving messages. Long range simplex communication is achieved with the LoRa RFM95W. 

The smartphone or the PC only need to have an application installed. All messaging, encryption, decryption and receiving is done on the device. It is battery powered. The LoRaSleeve could help communication in places where network reception is poor. Underdeveloped communities could benefit from its service. 

I will update this as the project progresses.


The complete LoRaSleeve design files.

RAR Archive - 260.36 kB - 03/18/2019 at 11:44


  • 1 × ESP32-PICO-D4 Microcontroller
  • 1 × HopeRF RFM96W
  • 1 × Battery Evaluation, Demonstration Kits, Boards and Modules / Evaluation Kits, Boards and Modules
  • 1 × AP2122 Power Management ICs / Linear Voltage Regulators and LDOs
  • 1 × MCP73831 Power Management ICs / Power Supply Support

View all 6 components

  • With Love from China.

    Taiwo05/24/2019 at 05:23 0 comments

    It took quite a while for the PCB to arrive from China. Who knew China is that far away from here. The overall build quality of the PCB seems okay but I noticed a little problem. The board was a little bit bigger than what I  had in my head  and  I added too much features for such low-power hardware.

    It was probably due to the fact that it is my 4th board (noob alert) and I am still struggling to get my dimensions well. Also because I was a little too ambitious. At the end, I decided to 

    • Reduce the number of buttons drastically and allow tweaking of parameters via Wifi/BLE.
    • Use ESP32 Wroom 32 for the next revision as they seem small enough for what I  intend and I have(finally) experience soldering and troubleshooting them.
    • Include a LNA and SMA antenna on the board without compromising its size. Probably a removable antenna or something similar.
    • Make a repeater with better specs and to reduce the transmission time and power required by LoraSleeve.
    • Find a way, if I can, to implement my own RFM96W on board. This does not seem very likely but who knows.

    One important reason for switching to ESP32 Wroom 32 is its availability on Aliexpress compared to Esp32 Pico D4. And Aliexpress (3 weeks) seems to ship faster to my place than Lcsc (still waiting).

    I am definitely not wasting 40 pieces of PCB (39 is okay). I will definitely populate at least one in the coming week ( when LCSC finally comes through)  and will get started on the software.

    I will make a log about the new schematic and layout soonest.

  • Ordering and Panelizing PCB

    Taiwo04/02/2019 at 06:26 0 comments

    I have known about JLCPCB for a while and thought of giving them a try for this project. The PCB is a small one and to save money I thought of panelizing the PCB. I'll have more PCBs for the same price. YAY. There was only one problem, I had no idea how to go about it. I went off to google and searched. I got a couple of cool options. Some easy and others not so easy. 

    After deliberating with google and very helpful guys on the HackChat, I settled for GerberTools ( This awesome application has a cool GUI and quite efficient gerber Panelizer. I took me a while to  get the hang of it for I had dimensioned my board on the copper layer (yeah, who does that?). I finally got it to work by removing the dimension and using DirtyPCB's cam files on eagle after it turned out that the app was no fan of the .gbr format. Below is the result I got after panelizing

    Notice the absence of traces in the bottom layer. Thats a bug I hope the maker of the gerber viewer fixes. I displayed it quite well on JLCPCBs gerber viewer though. Well, I am sure the PCB is very well on its way down and will be available in a few weeks.

    NB. I'll update the PCB file again (Sorry)

  • Finishing Up and Cleaning Up

    Taiwo03/18/2019 at 11:37 0 comments


    It took a while for me to notice a "little" error in the previously posted schematic. I missed a pull up resistor for the buttons and misspelled some net names . Fortunately, I noticed it before starting the layout of the PCB. In my bid to correct the mistake, I thought it wise to review the components used with the device and made the following changes.

    • I removed the OLED in a bid to reduce the power consumed and since all that it display could be inferred by other means (via LED and the PC/smartphone itself).
    • I reduced the number of buttons to two.
    • I added another LED for power and connection indication.


    I began laying out the components on the board with the aim of making the  PCB as small as possible. There was a limit to its size as I used 0805 components for easy hand soldering ( I can't cope with smaller components ,YET ). I used the ESP32 Pico D4 chip for smaller size. The PCB measured 5 cm by 3.6 cm at the end.

    The new schematic and layout has been uploaded in the project page. Off to JLCPCB...

  • Let's Begin

    Taiwo03/14/2019 at 16:50 0 comments

    SO FAR...

    When I created this project page, I had no LoRa module at hand . I still don't, but I had to get started. I checked my stash of unused components, and found a pair of NRF24L01.

    An RF transceiver, that is not LoRa.

     I played around with its transmission and reception of  messages. I used Serial via the Android Arduino application serial console on both phones. It worked, not well enough, but enough to prove a point. 

    My Android development skill is close to non-existent, and I hope to use Thunkable to make an app that interfaces with the ESP32 Bluetooth and sends and receive message from the hardware.


    I began making the schematic diagram early this morning. The device was to have 

    • A small screen to display basic information like battery level, number of connections  etc.
    • A rechargeable battery 

    I  used 0805 components and the ESP32 Pico D4. The PCB layout is not complete and I thought I'd share the PDF of the schematic.

    This is the progress so far.

View all 4 project logs

Enjoy this project?



Wo King wrote 4 days ago point

I am new to LORA so please be patient. Is there a restriction due to legally how many messages can be sent per hour?

  Are you sure? yes | no

kiu wrote 4 days ago point

Yes, there are legal restrictions (ISM Band usage) and depending on which LORAWan network you are connecting to, the provider has its additional rules and costs (when its a commercial network).

TTN is a good start: and

  Are you sure? yes | no

don.vukovic wrote 4 days ago point

Please reload  LoRaSleeve_PCB.rar, it seems to be corrupt.

  Are you sure? yes | no

Taiwo wrote 2 days ago point

Thanks, I will.

  Are you sure? yes | no

yusuf kehinde hussein wrote 03/31/2019 at 08:01 point

This is a cool one. 

  Are you sure? yes | no

Taiwo wrote 04/01/2019 at 11:15 point


  Are you sure? yes | no

Taiwo wrote 03/07/2019 at 05:26 point

Thanks a lot.

  Are you sure? yes | no

Josh Lloyd wrote 03/06/2019 at 18:24 point

This is a very cool idea. One thing I personally think will be important is end-to-end encryption between devices. Especially if the relays are open source 

  Are you sure? yes | no

Taiwo wrote 03/06/2019 at 19:38 point

Yes, that's a good one.  I might have to learn a thing or two to implement that though.

  Are you sure? yes | no

Josh Lloyd wrote 03/06/2019 at 21:22 point

When you eventually get there I'd be more than happy to help.

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates