GPS Module

I'm trying to hook an Arduino UNO to a Parallax PMB 648 GPS receiver module with cables.
I have connected it as follows, Parallax-arduino uno
Vin-5v
Gnd-gnd
Rx-rx
Tx-tx

Where do I put
Txd
Rxd

Thanks

The specification (http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/PMB-648_Specification_V0.1.pdf) shows:

pin 1: TTL TX
pin 2: TTL RX
pin 3: VCC (3.3-5v)
pin 4: GND
pin 5: RS232 TX
pin 6: RS232 RX

I thin you wire it this way:

pin 1: TTL TX -> Arduino RX
pin 2: TTL RX <- Arduino TX
pin 3: VCC (3.3-5v) <- Arduino 5v
pin 4: GND <-> Arduino Grond
pin 5: RS232 TX (UNUSED)
pin 6: RS232 RX (UNUSED)

pin 1: TTL TX -> Arduino RX
pin 2: TTL RX <- Arduino TX
pin 3: VCC (3.3-5v) <- Arduino 5v
pin 4: GND <-> Arduino Grond
pin 5: RS232 TX (UNUSED)
pin 6: RS232 RX (UNUSED)

So i just leave pin 5 & 6 loose?
I'm totally new to arduino, so i'm not sure of anything
Thanks!

I saw on ladyada that an led should light up on the module if it is getting power. My arduino is getting power, but nothing is lighting up on the gps module. my connections are

pin 1: TTL TX -> Arduino RX
pin 2: TTL RX <- Arduino TX
pin 3: VCC (3.3-5v) <- Arduino 5v
pin 4: GND <-> Arduino Grond
pin 5: RS232 TX (UNUSED)
pin 6: RS232 RX (UNUSED)

Is my module faulty? Am i hooking it up wrongly?
Thanks!

I don't have a multi-meter, but will consider getting one, though I can't today. I'm pretty sure that the 5V works because i have different components hooked up, and the worked just fine.

I just bought it from Robotshop. Is there any way i can make sure it's broken, so that i could exchange it or something?

Thanks for your help! :slight_smile:

I can't tell from the datasheet what the LED does as it's apparently used for two purposes, although I suspect it should show something all the time when power is on. On the offchance that it doesn't though, try wrting a little sketch that reads from the gps ttl lines using newsoftserial and echo what you get to the serial monitor. Another possibility would be to power the gps from some AA cells to eliminate the Arduino power as the issue.