The distributors finally got in some of the new ST Micro STM32F2 series uControllers and I grabbed a few. I was able to "shoehorn" one into a ver5 board as the pinout is close to compatible with the performance STM32F1 series. Spent a few days rewriting the device drivers and am very impressed with this controller's performance.
I was able to bump up the sample rate to around 276.8KHz for all 12 sensors for a total of ~3.32 million samples per second. Despite this more than doubling of work load, I ended up with around 70% idle time, up from 60% of the STM32F1. Keep in mind that at a 120MHz clock rate, this 70% free cycles represents more than twice as much free number crunching capability than the STM32F1 at 60% idle. I also found that the DMA to be much better with full FIFO available on each DMA channel and an easier to use triple ADC.
The result is a much cleaner interpretation of the sensor data which translates to a smoother and more stable platform.
Comments
..and you did it, again! :-)
Arducopter guys still struggling to release a decent stable version on the old atmega, and you test high speed navigation :-)
By the way, the last slow piroette in position hold is really good (at least compared to what you can do with MK in position hold in windy condition). What are your plans, now? Will you release the new code and hardware specs? Will you produce the board or sell a kit?
Maximus: All waypoints are in 3D coordinates
ThomasB: I think any STM32F2 code will wait for v6
CW: Wind - I can't say I know exactly. I live in a valley between two mountains and the wind is typically very gusty. I'm fairly sure the gusts were over 10mph, but I can't say with any certainly how much more. Take a look at some of the trees or bushes in the background. Some of them are moving quite a bit. The horizontal hold can handle a lot of wind and gusts, but they effect the vertical more as vertical is tied to air pressure which changes as the gust moves through. The error is tempered by the accel integration, but you have to rely on the pressure reading to correct them.
vis.asta: v6 information will be posted in another blog entry when I've had a chance to test.
This is incredible, by far the best afforable stable quad I have seen. keep up the good work and maybe we can all learn from you.
Nice to see your improvements to V5. Still the stablest flightplatform I've seen.
I've got some F205 yesterday and would be interested to see the codechange from F103 to your F215.
Will you checkin the new code in the autoquad googlecode project ?
Did you set the altitude of your "home" point ?
This fly is a "dream" !!!
Great job again Bill !!!
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