A7 Tracker

Tracker based on Elecrow 32u4 with A7 GPRS/GSM board

Prerequisites

• Arduino IDE 1.8.3 or greater
• ArduinoJson V5.13.5 library (install via Arduinos library manager)

Getting Started

• Clone this repository
• Change server addresses in A7.h

Setup

• modify settings from config.h

Data structures

Position update

Tracker sends this message to the server:

{"id":"254574","fix":1,"uptime":4115154,"signal":31,"batt":89,"lat":"5106.9792","lat_d":"N","lon":"11402.3003","lon_d":"W","nSat":8,"acc":7}

Key	Possible values	Comment
id	000000-999999	last digits of device IMEI
fix	0,1	availability of GPS signal
uptime	0-4294967296(~49 days)	tracker uptime in milliseconds
signal	0-33, 99	signal strength, reference
batt	0-100	battery charge level
lat		latitude, (d)ddmm.mmmm format
lat_d	N, S
lon		longitude, (d)ddmm.mmmm format
lon_d	E, W
nSat	0-20	number of satellites the receiver sees
acc	0-100	accuracy in meters

Settings update

Tracker expects this response from server:

{"loc_interval":"60", "set_interval":"100"}

Key	Possible values	Comment
loc_interval	0-4294967295	Location sending interval in seconds
set_interval	0-4294967295	Settings fetching interval in seconds

Changelog

V2.0 (Apr 2020)

• new functions

  • send battery level
  • send network signal strength
  • watchdog timer
  • non blocking delay
  • check that modem is alive and connected
  • send message even if no GPS fix
  • switch GPS off when not needed

• enhancements

  • move modem related code to AiA7 class
  • simplify sendAT function

• bugfixes

  • GPGGA parsing bug
  • reboot modem correctly