Custom LoRa Pager Designed With Care

LoRa is a useful technology if you need to send data a long way at low power levels. Leveraging this, [5Volt-Junkie] decided to build a small pager named the LoRaNicator.

Those who love a detailed build log will enjoy this. The pager features everything up to and including the kitchen sink. A Cortex M0+ runs the show, flashed with an Arduino compatible bootloader, while a RFM95W module handles the LoRa communications. There’s a pager vibrator and piezo buzzer for notifications, along with a LiPo charger to make keeping the battery topped up easy. There’s even an RTC and soft-power button module.

Even if the LoRa side of things isn’t relevant to your interests, it’s a great example of how to build a useful tool rather than just a proof-of-concept. Things like an easy-to-use interface and simple battery charging go a long way to making something usable in the field. [5Volt-Junkie] even goes so far as to point out that even solder mask matters – if you’re using an infrared oven, your black boards will need a different profile to the usual green PCBs.

All the hard work has paid off, creating an attractive end product that we’d be proud to pack with the rest of our ham gear. LoRa is a useful platform, and as we’ve seen, it can be useful for everything from viticulture to meterology. Video after the break.

13 thoughts on “Custom LoRa Pager Designed With Care

    1. I am planing to install something like this in my cars android nav. system.
      My wife does not want a cell phone. So at least I’ll be able to txt her when she is out.
      I am at a very nice height were I live.
      I have picked up 2 lora 5 watt Transceivers.
      And have the box for my house antenna ready to go up.
      I’m hoping to get at least 10 – 15 km. and around 25 km in the north direction.
      The university has a open lora network that I can connect too.
      I do wish that I didn’t live by a airport. I really would of liked to put the antenna up a lot higher.

      And Yea. What is the range that you think you’ll get?

      1. If your in the USA 5 watts is *well* outside the legal bounds for a unlicensed band. 1 watt is max transmit and 4 watts EIRP max. If you have any hams nearby that really like the 900mhz band I wouldn’t be surprised to see them hunt you down and point the FCC at you.

        Make a pager using a particle boron or similar LTE device. Its only a few dollars a month and would be vastly more reliable (and won’t upset cranky old hams).

        1. Or just operate at 1 watt into a ground plane vert, with good height above ground, using one of the slower lora modes, it will go pretty far!

          Or, get your ticket (only Technician required) and then as long as you follow the other guidelines, you’ll be legally entitled to run more power than you have any practical ability to achieve.

    2. I didn’t test the range yet. I’ll build a second pager, so I’ve two identical devices. I made range tests with the previous version of the pager, with AI-Thinker Ra-02 433MHz LoRa modules + good stub antennas (S11 -14dB @433MHz) and reached ~2.2km in a small city / village. Since I’ve access to a VNA, I tested some 868MHz antennas and they all were crap. Looked like a normal WiFi antennas (good @ 2.4GHz, bad @ other frequencies). So I’m still looking for good 868MHz antennas.

      1. In the past I was working on a small project @ 222 MHz (1.25 meter band) and couldn’t find antennas that were available and affordable (poor student budget and all) so I made my own: a yagi using cardboard, masking tape (ran out of duct tape at the time! :P ) and solid core 28 AWG wire I had laying around. Surprisingly enough, it worked ok-ish!
        Just make sure to check your antenna design first to make sure it’ll work! :D

  1. This is cool. There are some HAM radio operators reviving old POCSAG pagers too. At least this you can use even without a license. Could be handy for portable notifications, or as a 2-way texting device without needing a whole cellphone service.

  2. LoRa datacomms at UHF typically has an order of magnitude range boost over regular modulation (FM,GFSK etc ) under similar conditions & Tx power. A 25mW LoRa output at 433 MHz is good for several km in easy terrain, with >10s of km possible line of sight.

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