[SOLVED] GPS module EM406a changing the baud rate

[chalani0088]

I'm doing a GPS based project and using EM406A module, I want to do a serial communication between the MC and the GP module, but this outputs at a 4800 baud rate, I want to make this to 9600 BPS inorder to do the serial communication properly,

Can anybody help me on this?

regards chalani

 

[jjeevan007]

go through the datasheet u will get know...........

normally the gps will auto detect the baud rate and support accordingly..........

 

[chalani0088]

Thank you for replying, I could set the baud rate to 4800 bps in my coding, now the problem is when i connected the module with micro controller it won't display anything on the LCD screen

But i could do my task by sending same NMEA sentece via my computer serial port to the mcu.

I can't understand why GPS module dont send any data

The output protocol of GPS modula has following specifications
Electrical Level: TTL level,
Output Voltage Level: 0V~2.85V
Baud Rate: 4800 bps
Output Message: NMEA 0183 GGA, GSA, GSV,

can someone help me on this?

 

[chalani0088]

The problem was solved this level translation of ttl to ttl could be acheived using sn7404 hex inerter, using its two gates this could be done easily.

 

[jjeevan007]

can u post your circuit and which is GPS u are using

 

[chalani0088]

i'm using em406a. I have attached main circuit and the buffer circuit seperately.

 

[jjeevan007]

i think it gives the output in both ttl logic and rs232 logic,

if u are using the ttl logic then u can directly interface with the microcontroller without any buffer or level converter

if u are using rs232 logic then u need to use level converter to interface with the microcontroller........

 

[chalani0088]

It has a rs232 communication method but the output is not in the rs232 voltage range. It has the output voltage range of ttl. but the problem was it out put 2.85 max voltage out and swings between 0 -2.85V. This was not enough to trigger the rx pin of pic. that's why the need of buffer circuit came up.

 

[jjeevan007]

its better if u use the max232 ic to convert from rs232 level to ttl level, we normally do this...............

any way if got the output then its not required..........

 

[chalani0088]

no, here max232 circuit doesnt work

 

[jjeevan007]

post the circuit with max232