Very very interesting
Where we can find a description and tech spec. of this and other devices?
I buy from LEMFO in China (
http://www.lemfo.com/) - I use LEM8,9 and 10 mostly - they will bespoke the units if you order enough. But as I say any Android 5+ device with GPS can be used in my system plus soon an ESP32 using the Lilygo Twatch will be added. If all you need is tracking then using the lillygo esp32 bloc with gps and cellular modules might be a cheaper option for you (
https://www.banggood.com/LILYGO-TTG...eft-hotproducts&cur_warehouse=GWTR&ID=6300912). There are some great cases like DIN rail and so on that you can make a good looking product OTS. Programming can be done in B4R for compatibility but there are issues with AES and other parts of the system in B4R so in fact we moved to Arduino (sorry Erel
) however everything else in is B4X!.
However, its not really the target that is the issue, its how you manage cell communications as most 3G and 4G connections are troublesome due to the way carriers limit long term connections, believe me its not rational at all! It all depends on what interval you REALLY need plus if you want to then be able to interact with the target you have to keep the return channels open and active. Also as has been mentioned there is an issue of our Chinese and Russian friends forcing their way into UDP/HTTP/TCP connections which caused horrible issues until we had a hardwired firewall and very strict whitelist policy in place (we got upto 100K attempts per day at one point in the first year!).
I use MQTT (they hacked that as well btw as did a prominent US university in the guise of 'teaching') but as I encrypt everything AES256 they only can ghost messages and as time is included in each message then i can trach anything that's not real. I tried a wide range of protocols over a year getting to this point and I can say easily that MQTT is the most reliable and flexible for this - I even stream audio over MQTT in emergency!
I have three effective systems which are all compatible - but one is WiFi with Cell backup, one Cell data with SMS backup and one SMS only. All report location 24*7 at between 1 and 15 min intervals from augmented GPS.
If you wish to discuss further (remembering that this is a commercial system I sell and therefore I cant share everything) I am happy of you want to pm me
ehsebusiness@gmail.com or I can share bits on the forum.