HMC5883L Magnetometer chip Possibilities.

[towlerg]

Andy, you still have North and East reversed and South and West reversed as well, North is 0, East is 90, South is 180 and West is 270.
http://commons.wikimedia.org/wiki/File:Compass_Card.png Although I guess you'd be better off saying greater than 315 or less than 45 it's North.

George

BTW I'm trying and failing to get a 5983 (supposedly updated version) working with little or no success, I think I killed it!

[andybarrett1]

Hi George

I think the reversal on the last bit of the code is to do with headings and angles etc.. So not all that worried.
Is the 5983 the same layout as mine... If so will the code not crow bar into it ?

Am also not to sure about gain settings etc.... Have left mine at default.

BR
Andy

[towlerg]

My understanding (perhaps wrong) is that 5983 is an improved version of 5883. It is temperature compensated and will output at a greater rate appearently. I'm working on the assumption that it is software compatible - but you know what they say about assume.

George

[towlerg]

I can't edit my last post and I wanted to add

My understanding is that you want the gain as high as possible without saturating. X,Y and Z values are in the range -2048 to 2047 so I guess you're looking for something like -1500 to 1500.

I see you don't allow for declination, the difference between magnetic and true north. You can get your local declination from http://www.magnetic-declination.com/

I'm assuming the the X coordinate points North, although now I think of it I can't see why. the only reference I can find is "Arrow indicates direction of magnetic field that generates a positive output reading in Normal Measurement configuration" take from that what you will.

George

[andybarrett1]

Hi George

I agree with gain... Reading the datasheet seems to be way to go ... If it over saturates you get the -4096 figure.

I also am assuming that X is north... Certainly shows like that at in most of places I have looked.

Y seems to be either West (left) or East (right).... depending on what you look at... I did find a useful Honeywell document yesterday, will post a little later on.

There is certainly a shortage of info around as to how to use these devices with PicBasic

BR
Andy

[towlerg]

Are you using one of the break-out boards, GY0281 or GY282? Could you post a circuit diagram? The two break-out boards above both have 3.3v regulators on them, I'm curious as to what Vcc you run the PIC at and if you use level changers. If X is North Y must be West. George

[andybarrett1]

Hi George

This is the exact one I am using ... The ebay link has Pics and Circuit... I am running it at 5v.. As the LCD needs 5v

http://www.ebay.co.uk/itm/1112141408...%3AMEBIDX%3AIT

BR
Andy