[Paparazzi-devel] Thermopile replacement

[Jesus Martin Sanchez]

Hello:
  I found this stuff in the web:
  http://www.ryanmechatronics.com/index_files/ProductDetailCHIMU.htm
  And this one:
  http://www.ryanmechatronics.com/index_files/AnalogNode.htm

  I ask their, about how interconnect it in a device (paparazzi) that use the z sensor too.
  They answer me this:

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Hi  Jesús,

 

We’ve never used the thermopiles directly, but we have others that are integrating the CHIMU and Analog Node into their planes.  My understanding is that the Z sensor used by IR based autopilots is needed because if you roll past a certain point, then the sensors are ambiguous.  In other words, if  you go inverted, then the sensors think that is o.k. level flight.

 

We do not have a Z sensor output, because our output analog value always gives the right value.  If it is inverted, you get a different voltage than if you are level.

 

As for programming, we’ve never had anyone implement it with Paparazzi before.  If Paparazzi needs a Z sensor input, you’d have to program your code to ignore that correctly.  Also, we don’t know if the gains for Paparazzi work “out of the box” with our unit.  It should, but to be honest we  haven’t done it.

 

As an example, one customer using the unit with the Ardupilot from DIY Drones said that the Ardupilot code tries to calibrate the IR sensors when it boots up to run.  Since the CHIMU doesn’t do any calibration, he had to start the autopilot, then plug in the CHIMU.  So he didn’t have to change any code, but did have to develop a work around.

 

As for programming the CHIMU, no you don’t have to.  If you decide to order, let us know in the comments your latitude and longitude and we’ll program the magnetic field vector in for you.  You may want to order a USB Node as well however, as it is fun to look at the data from the CHIMU during ground use…

 

Good luck with your project!

 

With regard,

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  Anybody has an idea of how connect it?

  Thanks

  Jesús