I am trying to design an employee tracking system, to track employees from room to room, for saftey purposes.

Somewhat obviously, if requires each tracked person to carry a device which uniquely identifies them.

Which will obviously have to be battery powered, with enough battery life to last a full working shift, let's say 12 hours?

It is becoming apparent that I am looking at Bluetooth Low Energy – unless someone can make a compelling argument for WiFi, ZigBee., etc.

Please, bear in mind that the device and battery must be worn in an industrial environment, so should be robust, and also easy to charge when needed – at worst overnight, ready for the next shift.

The device need only identify itself, as it passes various access points (presumably by pairing with them, or offering to do so?)

Looking at the List of Bluetooth profiles , I am guessing at the Proximity Profile (PXPP) ?

In any case, what I do not want – close as it is - is a cheap sports/fitness band. What I would like is something very like that :

  • Rubber wrist band – nice to have, but not mandatory
  • Rugged & robust – is quite important
  • Button/cell battery – for small form fit
  • NO built in apps, e.g. health / fitness
  • It would be nice if I were able to load my own software. For instance, to vibrate the band remotely, or display messages. What I don’t want is lots of built-in fitness tracker stuff, which is not associated with my system

The Flora Wearable Bluefruit LE Module looks good, but

  • it’s not totally off the shelf : “Sew 4 traces (or solder 4 wires)”
  • There is no indication of battery life (although I don’t expect any problems with BTLE)
  • I would prefer something worn on the wrist, but could live with this

On the plus side it seems easy to program “After you connect to the Bluefruit, you can send commands wirelessly in under 10 minutes”. Also, “Built in over-the-air bootloading capability so we can keep you updated with the hottest new firmware. Use any Android or iOS device to get updates and install them” seems a big plus.

Is there any other cheap (preferably sub $50) wrist wearable which is programmable, preferably with a snap-in coin/cell battery?

[Update] I now have a strong preference for BT 5, rather than v4, but can't seem to find any. The reason being that the BT 5 spec has provisions for proximity, which could save me a lot of effort on triangulation.

  • 1
    See this company: litumiot.com/employee-people-tracking – Digital Boffin Feb 23 at 20:35
  • Looks great, and is pretty much what I was planing to develop. It uses RFID, though, not BT. I could live with that, although it obviously has to be active RFID, not passive, which dries up the price of the readers. Hmm, I just read further and their readers will also detect BT-LE. I will contact them, as their underlying infrastructure interests me, but I really want to develop the software which acts upon employee location myself (plus maybe also transmit to BT). A great comment - feel free to post it as an answer - but I am still looking for the wearable :-( – Mawg Feb 24 at 8:05

I am answering my own question, in case it is of any interest to others.

For development, I have found an excellent and extremely cheap solution. In fact, it could probably be used in non-profits. Only for a commercial product would I need to have something custom manufactured, as I can't find a COTS solution (needs to be smaller, more rugged, with a better battery).

So, for US $14.90, plus postage, I found this:

M5Stack Multi-function Watch! With 700mAh Battery for Arduino & Micropython ESP32 Core Intelligent Programmable Watch with Band

It's slightly chunky, and I don't like only having a 700 mAH battery (but the ESP32 has great power management), but it's more than good enough for development.

enter image description here

enter image description here

Hmmm, the Google cached version of the page shows it as costing less ($10.70), with a batter (850 mAH) battery. Strange days indeed!

Also,this one looks smaller, with a better form factor. I will have to enquire where to but it & update this answer. enter image description here

[Update] from forum.m5stack.com/topic/548/m5stick-watch/9

the original stick can be purchased via the following links: https://www.aliexpress.com/store/product/M5Stack-Official-New-M5Stick-Mini-Development-Kit-ESP32-1-3-OLED-80mAh-Battery-Inside-Buzzer-IR/3226069_32994893797.html?spm=2114.12010615.8148356.13.25ba781bqWZV2X


The main differences between the stick and stick c are that the stick c has a smaller screen but it is color opposed to the monochrome oled of the original, the power management chip is different, there are a bunch more sensors added etc.. for a detailed comparison you can check the docs pages for both the stick and the stick c

https://docs.m5stack.com/#/en/core/m5stick https://docs.m5stack.com/#/en/core/m5stickc

Also costs sub $15

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