[Paparazzi-devel] CHIMU Integration - Wiring and Configuration

[Cameron Lee]

Hello everyone,

My name is Cameron Lee and I'm an engineering student at the University of Alberta. I'm trying to implement Paparazzi as part of a student group; the University of Alberta Aerial Robotics Group (UAARG).  We're using a TWOG, Leah GPS, XBee (although we're working on XTend) radio, and the CHIMU IMU. We've done a test flight with just the XBee and GPS working - we were able to see where the plane flew on the ground control station. Now I'm trying to get the CHIMU working, and I've been having troubles. If anyone knows the solution to my problem, that would be great.

We've got our CHIMU working with the GUI (although we get App Errors every once in a while, such as: XSUM fail! MsgID-2), but when connecting it to the TWOG over SPI, Paparazzi's ground control station always shows the attitude as perfectly flat - it gets altitude messages every second, but they're all zeros. I've connected Vin, GND, SCK, MISO, and MOSI between the CHIMU and the TWOG. I've also connected the SSEL of the TWOG to GND (and I tried +3.3 V at one point too). The yellow light on the CHIMU flashes, so I know it's getting power. I've included the following lines in my airframe file (along with all the other lines - the full file is attached):

  <modules>

      <load name="ins_chimu_spi.xml" >

      <define name="CHIMU_BIG_ENDIAN" />  

  </load>

  <firmware name="fixedwing">

      <subsystem name="spi_slave_hs"/>

  </firmware>

I've also tried without the CHIMU_BIG_ENDIAN line. I've however read that this is only for the CHIMU J, so I think I do need to have this line.

During my troubleshooting, I've used an oscilloscope on the SCK and MOSI lines. There seems to be a regular clock pulse on the SCK line as well as data on the MOSI line. I also tried plugging the CHIMU into the TWOG after the TWOG had booted up and connected to the ground station. When I did this, before connecting the CHIMU, the messages come in, but are all zero - i.e. the same thing as when the CHIMU is plugged in. But, once I've plugged the CHIMU in, with the SSEL set to +3.3V. and with the big endian line, Paparazzi Center displays:

Failure("Pprz.values_of_payload, too many bytes: 00 03 03 29 00 00 00 00 00 00 00 ")    (I don't remember exactly how many pairs of zero, but there were a few)

Failure("Pprz.values_of_payload, wrong arguement: 00 08")

and no attitude messages come in - in the messages window, I can see the time since the last attitude message increase.

When doing this but without the big endian line, the same thing happens except without the "too many bytes" line (maybe because of the timing I plugged it in).

When doing this but with the SSEL set to GND, I don't get these failures, and the attitude messages with zero values keep coming in.

Does anyone know what I need to do to get the CHIMU working?

Thanks,

Cameron Lee

address@hidden

IMG_20120321_233138 (1).jpg
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ChimuJTinyFwSpiModified.xml
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