Notice the red wire on the PPZIMU .. it's a jumper to simply route the power pin direct to the 3.3v rail on the board. I modify PPZIMU this way after removing the 5v regulator. The 5v power on the servo rail is very dirty (i.e. not clean 5v). So powering the PPZIMU from 3.3v seems to help with noise. To get 3.3v to the IMU I wired this way or you can use the 3.3v from the GPS connector. The PPZ GPS13 can be powered from 3.3v if you wire the connector to the 3.3v pin on the PPZ GPS13.
If you power the PPZIMU modified this way with 5v that would be bad and damage it.
Everyone may notice that PPZ9DOM IMU is not available on the web store. This is because so many people have complained about them not working. I have no idea if it's how they are connected or a real problem because I myself have flown with it for a long time along with others. If you must have these sensors (HMC5843, ITG3200, ADXL345) then SparkFun does make a sensor stick with these sensors. In the meantime I am only suspending selling this IMU until I am certain what is going on with users having a difficult time with them.
I see someone is making an Eagle design from the schematics I sent them. I encourage you to add transistors to protect the boards from over voltage, wiring errors etc. This board as designed is easily damaged.
Regards,
David Conger
On Nov 5, 2011, at 2:58 PM, Jorn Anke wrote:
Red wire to sp1/ the 8th pin on the right side of the board