Interface with GPS please help me.

[Pawan Kumar]

Hello gurus,

 

I ve used this web site a lot to learn 8051 controller programing thanks .  

I am doing my final year project with ARM7(LPC-2148). I need your help here.I  have to interface G.P.S with microcontroller for which I am using your code as the reference.

http://www.engineersgarage.com/microcontroller/8051projects/gps-interface-8051-microcontroller-circuit

I do not understand two things:

1)In the main ()

void main()

{

serial();

lcd_cmd(0x38);        //2 LINE, 5X7 MATRIX

lcd_cmd(0x0e);         //DISPLAY ON, CURSOR BLINKING

IE=0x90;

while(1)

{

if(check==69)

compare();

}

 

how is check value incremented to 69?

2)You have defined a function receive_data() but never used it

 

I am not able to understand how you recieve data, store it in an array . If you can help me with the step by step procedure, I would be grateful to you.

 

Thanks

 

G.Pawan Kumar

 

[Syed Aameer]

Hi pawan,

                  that recieve program is written with interrupt,so when data is recieved the data will automatically store in buffer.i.e., info[check];   info[check++]=SBUF; so when data is 69 means you have completed recieved data. so you can go for check $GGA,$GGL and other. to know connect ypur GPS receiver to hyperterminal and view what all you get.

for more information you can view NMEA protocol datasheet to know the data format from GPS

[Pawan Kumar]

Thank you syed,

I have not come across interrupt driven receive in ARM. I ll have to learn that and come back to your code. btw, thanks for the info.

[praveen]

but ameer in this same program i got problem in interrupt 4…….problem is the test array is not matching with data from gps…………….i tried all possible ways but i dint…….

[Author]

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