Replies to This Discussion

Permalink Reply by Josh Potter on August 17, 2012 at 10:04am

Ah, thanks for the information. 

I haven't gotten to that point yet.  I have everything wired up and working correctly, but I just got the correct ESC for my 500 heli. I was trying to power it on 4s (normally 6s), but couldn't get enough head speed to do anything.

• ▶ Reply

Permalink Reply by Jeff Smith on August 17, 2012 at 11:11am

DRDY is the the "data ready" pin which functions as an interrupt to the CPU. It basically tells the processor that the 5883 has new info to send.

The two methods of getting info from the 5883 are either to ask for it then read, or tell it to use DRDY when the info is available then read it.

DRDY is not mandatory...

• ▶ Reply

Permalink Reply by Jeff Smith on August 20, 2012 at 8:50pm

It appears that on the 2.5 they only cut the SDA line, should have occured to me that if you don't initialize the on-board 5883L that it wouldn't be sending any info on the I2C or tripping the DRDY either.... some time I feel like I'm lucky to tie my own shoes LOL.

I'm also sure that they are not using DRDY on the external mag either :-)

So, cut SDA and use the external I2C.... simple. If you were really handy I imagine you could even flow solder over your cut if you cleaned the trace and cut right at the via.

• ▶ Reply

Permalink Reply by Brad Pittevski on August 27, 2012 at 5:39am

Thanks Jeff. I'll give it a try. I've raised the whole APM2 by an inch for now and it made a big difference.

• ▶ Reply

Permalink Reply by Jeff Smith on August 27, 2012 at 5:54am

Well I've spent this pay periods play allowance getting all the hardware to build a variable pitch hexacopter, but I'll likely get an additional external mag for my spare "test APM 2.0" and try cutting SDA1 on it for the hexa. Should be a few weeks before I see the parts though, and I've got a 250 build using the ArduIMU V3 that I've been neglecting too...

Too much time spent working and never enough time for play :-)

• ▶ Reply

DeveloperPermalink Reply by R_Lefebvre on August 28, 2012 at 9:23am

So you think we can disable the Mag on APM2 by cutting the same line?  Any idea where exactly?

I have 2 APM2 boards that I would like to use, but cannot, because they need external mags.

Oh, and then the question is also: how to wire up the external mag?

• ▶ Reply

Permalink Reply by Jeff Smith on August 28, 2012 at 10:26am

Yes, I haven't had the chance yet to test it, but I have a 2.0 that I managed to resurrect after another person tried to cut traces to the GPS and ended up with a dead daughter board. I got it fully functional, so I can cut the SDA1 (the trace goes to a via within 1/8" of the mag) and plug an external unit into the external I2C connector to verify the mod. The via will with luck provide a good spot for a solder jumper later if I decide to use the on board mag...

I need to pick up a second mag first and that's at least 2 weeks away.

• ▶ Reply

• ‹ Previous
• 1
• 2
• Next ›
• Page