Concox

Run

node adapter.js

node simulator.js

Decoding GPS Packet

78 78 22 22 0F 0C 1D 02 33 05 C9 02 7A C8 18 0C 46 58 60 00 14 00 01 CC 00 28 7D 00 1F 71 00 00 01 00 08 20 86 0D 0A

Check

• Check the protocol number which is the fourth byte if it is 0x22 then the packet contains GPS packet.

Getting longitude and latitude

• Both latitude and longitude are 4 bytes , so checking the bytes 12-15 and 16-19 converting them to decimal and dividing by 1800000 will give us the latitude and longitude of the device.

Date and time

• 6 bytes are reserved for date and time . Starting from year , month , day , hour , minute , second each is assigned 1 byte. Covering them into decimal will give us the date and time. for our case

    0F 0C 1D 02 33 05

it will be 15 year 12 month 29 day 02 hour 51 minutes 5 seconds

Course and Status

• Two bytes are consumed, defining the running direction of GPS. The value ranges from 0° to 360° measured clockwise from north of 0°

• It is 2 bytes that means we can Convert it to binary number of 16 bits and calculate by its the information.

• first two bits define starting bits which will both set to 0,next four bits give us information of (north latitude, east longitude, GPS positioning and real time gps) last 10 bits give us information about the course and

• Example : the value is 0x15 0x4C, the corresponding binary is 00010101 01001100, which means GPS tracking is on, real time GPS, location at north latitude, east longitude and the course is 332°.