# GM862-GPS AT not working

**URL:** <https://community.sparkfun.com/t/gm862-gps-at-not-working/23554>\
**Category:** Development Boards\
**Created:** [March 8, 2012, 5:32pm UTC](https://community.sparkfun.com/t/gm862-gps-at-not-working/23554 "2012-03-08T17:32:53Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![JAM](https://avatars.discourse-cdn.com/v4/letter/j/f6c823/32.png) [@JAM](https://community.sparkfun.com/u/JAM)\
**Post date:** [March 8, 2012, 5:32pm UTC](https://community.sparkfun.com/t/gm862-gps-at-not-working/23554/1 "2012-03-08T17:32:53Z")

</div>

I’m using the telit GM862-GPS with a TI MSP430G2553 microcontroller. I can receive the debug echo from the serial communication but the device does not execute any of the AT-COMMANDs.

Hardware configuration

MCU—GSM

Rx ---- Tx

Tx ----- Rx

--------- RTS - GRD

--------- DTR - Pulled up

The voltage levels are within operating parameters.

I’ve played with the baud rate, every configuration I’ve tried ends with the same result.

I end all lines with ‘\r’. I’ve even tried:

\015

\0x0D

\0D

\0x0d

\0d

\r\n

\n\r

/r

/r/n

/n/r

And several other even more ridicules combinations, all to the same result, the echo.

What can I do to make this thing work?