SparkFun Forums

[jernej]

Hello!

recently I bought GY-GPS6MV2 GPS module.

I would like to send data from this module to
my arduino board without wire connection.
So the GPS module would be connected to the transciever, and
arduino board to the receiver.

My question is, is this possible with "433Mhz RF transmitter and receiver link kit for Arduino/ARM/MCU WL"
LINK: http://www.ebay.com/itm/433Mhz-WL-RF-Tr ... 0717845396

or with "RF transmitter STX882+ RF receiver SRX887"
LINK: http://www.pilotviews.com/products/433m ... g-antenna/

I am a bit confused, because it only has three connections on one side, and
i have rx and tx to send.

Is it possible with "433mhz rf data transmitter and receiver Module SV611",
that has rx and tx connections on both sides?

Another alternative is to connect GPS module to arduino with wires and then send data
wirelessly to another arduino.
Is that easier? What do I need for that?

Thank you all in advance:)

Jernej

[Valen]

Each pair of modules transmits only one way. You would need 2 pairs to get to transmit in both directions, but then they will likely jam each others transmission.

I think you can get more reliable transmissions in both directions easier with Xbees (802.15.4 aka series 1) Same voltage level as the GPS module and default baud rate. Also the modules are smart enough not to talk through eachother and have a bit of a buffer to hold the data until transmission.

It all depends on the requirements of the wireless connection though. Same goes for the wire connection. What is the range supposed to be? Why does the arduino need to be away from the GPS.

[jernej]

Thank you for the answer.

The comunication has to be only one way I think (from sensor to arduino).

Sensor has to be away, because I would like to make a differential GPS. One would be connected
to arduno, one would be away on a known point. Combining measurements from both sensors gives
us a vector between known point and current position of the other sensor (more accurate).

Currently I see the only solution in having arduinos on both locations and sending data from "base" arduino
to moving arduino.

[Valen]

I forgot to mention, the baudrate of the GPS is too high for these transmitter and receiver modules. 9600 versus 2400 baud. As these radio modules do not have any protocol that takes care of error detection or correction you have to program that yourself. Which reduces bandwidth even more. I really think you'll be better off using XBees because of this. I know the price difference is detracting, but if you go with those cheap radios you'll waste money, time and hair on your scalp trying to get it working.

[jremington]

With the 433 MHz modules and Arduino, you need to use either of the VirtualWire or RadioHead libraries for communication. I have had no trouble with VirtualWire and it is very simple to use -- start with the basic examples provided.

Unfortunately with those modules, the GPS module cannot be directly connected to the transmitter. There must be an Arduino in between, running a program to read the GPS and send the required data.

Combining measurements from both sensors gives us a vector between known point and current position of the other sensor (more accurate).

A form of this correction (WAAS) is already built in to most modern GPS modules and is available in north America. It doesn't help much, but I would be interested to know how you hope to improve on it.