Today I managed to get my first DC Easy Rev 1.4 up and running 😉 I wanted to do it at the CCCamp 2015, but I had very bad luck with the two first PCBs (assembly problems with our reflow oven which does not produce really reliable PCBs with fine pitch and QFN components). Only electronic geeks can share the insanely lucky feeling when at last a LED is blinking (but for this, of course we need a floating point ARM Microcontroller – ah well, a 555 Timer would also do, but everybody can do that!).
dragonCopter will be on the #cccamp15. Have a look at the CCCamp 2015 Wiki. The main goal will be to present the new DC Easy Hardware with a (hopefully finished) software, and to do some FPV flying experiments.
I posted some information about the DC Easy electronics in the electronics category. The DC Easy is really great: A complete quadrotor electronics with flight control and four brushless controllers on a single 50x50mm PCB (where others barely manage to put a flight control µC and some SMD resistors). The DC Easy hardware was created in 2014 but due to a lack of time, the software for it still is not ready, but is targeted for the CCCamp 2015.
I just re-built my largest 12″ quad, the “bumblebee” with the fireBLDC 1.2 brushless controllers mounted directly under the motors under round aluminum carrier plates. This is really the way these brushless controllers are meant to be installed:
Of course the cable routing could be better (inside the riggers and through the aluminum plate), but for testing/quick installation, this is ideal. The first two flights were excellent, the quad really makes a nice humming sound when rising at full throttle, like a church organ pipe ;-). The CAN bus makes it extremely robust, so no fears of I2C bus errors here, even with long cabling. I also put some position light LEDs at each end, because the fireBLDC supports to switch one LED for this reason. Sadly I decided to use only a microcontroller GPIO, so the LEDs are very dark due to the little current. For the next version, I will use more powerful LED drivers.
I wrote down the development history with some nice pictures of the logikopter and the first revisions of the dragonCopter hardware. See the about page. Having a look back sometimes gives a good prediction what can be anticipated in the future ;-).
What I currently look at: Invensense has its MPU 9250 coming up, which could be a nice replacement for the MPU-6000 6DOF Gyro/Acc and HMC5883L Compass in one chip package. So, less PCB space occupied and less different parts to source as well as a simpler serial protocol. Looks like the future IMU for quads! Also, I like the new ublox GPS module with an integrated patch antenna, the PAM-7Q. Too sad I am not a facebooker, so I can’t press any like buttons for that one. Both the Invense IMU and ublox GPS are upcoming products which can not be sourced yet, so there a nice candidates for an upcoming design.
When I started to develop the dragonCopter, I used Keil Realview MDK Evaluation (Code Size limited to 32KB) and some self-built Eclipse/Codesourcery solution which overcame the 32KB limit, but which did not work very well (especially debugging did not work well when it came to set breakpoints over Segger GDB Server). Since the project will grow out of the 32KB limit when it comes to navigation features, it was time to switch development tools to a free solution. I recently installed Coocox which is a very good eclipse based IDE for ARM Cortex Development. It works together with GCC ARM Embedded which is maintained by ARM developers and seems superior to the Codesourcery Toolchain. Coocox seems very nice, its only drawback so far seems that it is not yet ported to linux. But GCC ARM Embedded is ported to Linux, so development on Linux could be done with another IDE and makefiles for GCC ARM Embedded.
It has been quite a while since the last post. Becoming a father does not necessarily ramp up your time budget for your hobbies, but abandoning your hobbies does not necessarily make you a better father, because hobbies make you lucky. And when you are lucky, you can be a better father! So, whats up next? I always wanted to implement the navigation features such as GPS position hold/ waypoint navigation and the like. But until now, I only managed to implement a simple barometric height controller, which is a good start for navigation, but not yet the complete solution. So this will be my target for this year. I also switched my blog to the english language, so it is not limited to a german audience anymore.
Ever wondered how to transfer data over the air without radio waves? Here is the answer:
My Video of the Chaos Communication Camp 2011. This was a really epic event. Too bad that the location is permanently closed for future events. Had two real nice motodrones there in Finowfurt!