- Tue Feb 10, 2009 2:41 pm
#65862
Hi All,
Some guys in the office along with myself want to throw together a flying contraption. Long story short, this has led us to look at the use of brushless DC motors, and by extension to look for controllers for these animals.
The problem we're facing is that the commercial controllers seem to only support update rates of ~50 Hz, while we would desire an update rate of around 100Hz.
I'm torn at this point between finding a commercial controller designed for hobby flying that is known to be able to take updates at 100Hz (anyone know of any in the 25A range?) and building my own based on the numerous application notes from Microchip on the subject.
The former option would still leave me with some questions on the utilization of servos, as I've come under the impression that there is more to it than simply sending a PWM pulse at 50Hz... something to do with initializing the controller to allow it to detect the number of poles in your motor, etc etc every time one wishes to fly.
The latter option has the benefit of being able to update at extremely fast rates, and to modify the modules to take an i2c or spi bus so we could drive all four rotors from a single port, as opposed to needing to use up all of the PWM outputs.
Can anyone shed some light on my (mis)conceptions?
Thanks in advance.
-Cannibal
Some guys in the office along with myself want to throw together a flying contraption. Long story short, this has led us to look at the use of brushless DC motors, and by extension to look for controllers for these animals.
The problem we're facing is that the commercial controllers seem to only support update rates of ~50 Hz, while we would desire an update rate of around 100Hz.
I'm torn at this point between finding a commercial controller designed for hobby flying that is known to be able to take updates at 100Hz (anyone know of any in the 25A range?) and building my own based on the numerous application notes from Microchip on the subject.
The former option would still leave me with some questions on the utilization of servos, as I've come under the impression that there is more to it than simply sending a PWM pulse at 50Hz... something to do with initializing the controller to allow it to detect the number of poles in your motor, etc etc every time one wishes to fly.
The latter option has the benefit of being able to update at extremely fast rates, and to modify the modules to take an i2c or spi bus so we could drive all four rotors from a single port, as opposed to needing to use up all of the PWM outputs.
Can anyone shed some light on my (mis)conceptions?
Thanks in advance.
-Cannibal