GPS Interfacing with Microcontroller

[Sathiesh Kumar]

Hi to all,
Happy New Year...
When i interface a GPS receiver with 89c51 microcontroller... i can able to receive data using UART but when i display it in LCD it shows random characters... often shows D with few other characters like j,s,p,t,u,w....
What mights be the problem...
I have written the coding in MikroC compiler for 8051...
Baud rate :4800 bps

Help me.....

 

[kchriste]

You are aware that the GPS data is usually encoded in NMEA ASCII format? Google NMEA 183.

 

[Oznog]

Not all GPS start from the NMEA-183 specified 4800 baud rate.
A serial GPS with RS232 output is the wrong levels for inputting to a microcontroller, and it's also the inverted. You need a level shifter like a MAX232 to make those compatible with a uC. But, bare GPS modules usually DO output 5v/0v levels, without inversion, instead of RS232.

 

[mramos1]

Hi to all,
Happy New Year...
When i interface a GPS receiver with 89c51 microcontroller... i can able to receive data using UART but when i display it in LCD it shows random characters... often shows D with few other characters like j,s,p,t,u,w....
What mights be the problem...
I have written the coding in MikroC compiler for 8051...
Baud rate :4800 bps

Help me.....

Confirm your data from the GPS is 5vdc (do you have a scope). If it is not 5vdc, here is a simple interface circuit.

Simple RS232 to logic level converter (TTL, CMOS)

Then try flipping the code to inverted on the serial open. And try some other baud rate combos.

OR get the manual for the GPS you have and see if it tells you the output should be.

 

[jeminshah]

urgent help required:

hey i require information regarding gps interfacing with mew p..

can u please suggest me which gps should i use along with the mew p specifications also which would make things easier...my objective is to obtain the lat/long from the gps and then send it using RF transmitter...

 

[kamdy]

You have to check two things the first is baud rate of the GPS receiver must be the same as the UART of the microcontroller and the second thing is to check the data coming from the GPS may be it is inverted so use inverters to invert the data before you read it by the microcontroller

 

[blueroomelectronics]

What's a "mew p"? sounds like a cat.

 

[Nigel Goodwin]

What's a "mew p"? sounds like a cat.

Presumably the greek letter 'Mu', used as the prefix for micro.

 

[Dr_Doggy]

I am having same problem with my LCD, it is something to do with start/stop bits or bit length....

 

[DirtyLude]

Why are the urgent requests always requests for total project design advice? I can't remember ever seeing an 'urgent request' that had a specific answer; They are always things like "I need to make a touchscreen smartphone. Please suggest any hardware that is required and describe its function. Thanks you."

 

[jeminshah]

thanx kamdy for ur help