Which compass module is easier to use?

Projects General Guidance
1

Hi,

I am developing a remote controlled hover craft using Arduino and Xbee.
Just thinking about putting up a compass module to get realtime heading of the boat. (Xbee will transmit the heading data to may laptop where I will translate it into a graphical representation)

Any suggestions? as to which module is easy to interface and accurte too?
i heard that HMC5843 is very difficult to calibrate and requires a lot of blood & sweat to understand and implment :wink: any opinions please.

I also plan to install a GPS module later on, since I can get heading/direction from GPS too, does it eliminate the need of an external compass? Please don't mind if my questions sound silly, i am pretty knew to this arena.

2

does it eliminate the need of an external compass?

No, A GPS can only give heading if it is moving.

3

Thanx AWOL, ya that's a fundamental difference to note.
Any light on a "beginner's compass" for me?

I dun mind spending hours n hours on R&D but I normally start with the
simplest possible one n then gradually climb my way up. That's why looking for any suggestions as to where to start from when it comes to Compass?

4

Really depends on your requirements. The Honeywell HMC6352 (http://goo.gl/PBPlt) is fast, accurate, and very easy to integrate into projects; I've also used the HMC5843 which is cheaper but not quite as accurate. Both are i2c devices.

5

Thanx buzzdavidson,

Let me get one and give it a try.
Any hint on how to calibrate it? As per what I have Googled so far, if it's not calibrated, it doesn't give meaningful data.

6

I managed to get hold of one HMC5843. I have also found a tutorial but in tutorial it's connected to Arduino thru a level shifter as it operates on 3.3V.

Cannot I use the 3.3V pin directly from Arduino? I am using Arduino Uno and it has 5V and 3.3V out.
I couldn't understand why level shifter is used? Can anyone shed some light please?

7

I couldn't understand why level shifter is used?

Because the logic levels are incompatible between the 5V Arduino and the 3.3V module.

8

That's what I meant AWOL. When Arduino also has a 3.3V power out, cannot that be used to connect to 3.3V module?
I am from a software background having least knowledge of electronics. Your help will be greatly appreciated, if I am missing some basic concepts.

9

When Arduino also has a 3.3V power out, cannot that be used to connect to 3.3V module?

Yes, you can use that to power the module (provided it doesn't take too much current), but the logic signals will need shifting to match the two devices.

10

Yes, you can use that to power the module (provided it doesn't take too much current), but
the logic signals will need shifting to match the two devices.

Thanx a lot, lemme give it a try.

11

I got it working .... :wink:
Thanx to all who helped.