bigmoose
1 MW
Stuff at random:
Support of Alan's choice of Stella: (80 MHz part)
***Alan have you been able to determine which is "better" or how key characteristics differ between Stella and Piccollo for motor apps? We know it is out there somewhere in TI space, but I haven't been able to find it. It looks like Hercules is the top dawg, but it is 2x the cost and a larger board as you said. The control card pushes $100 in lieu of $45 ish.
Support of Alan's choice of Stella: (80 MHz part)
Finally, the Stellaris family features peripherals designed specifically for intense industrial motor control, including motion control PWMs and quadrature encoder inputs...Single-cycle multiply instruction and hardware divide. (Mandatory IMHO) All StellarisWare software has a free license and royalty-free use to allow the creation of full-function, easy-to-maintain code. (TI "got it" Home run on this one. Make the tools free and available. Sell more silicon.)[/quote
I fully agree that sensors (some type) are mandatory for starting.
Heading forward I see the need for better position measurement. I have been researching magnetic angle encoders. I could never figure an elegant way to incorporate them on outrunners. Hence more interest these days in inrunners. That won't solve the hub motor issue with an encoder, but halls may be enough. Amberwolf had a wheel chair (Invacare?) hub motor disassembled one time and showed me pictures of an "analog type" hall used as a sin/cos position sensor. I would really like to know more about how they did that.
C2000 series:
The C2000 controller uses a central 32-bit CPU core, called C28x, coupled with a highly optimized peripheral and interrupt management bus. As a cross between a general microcontroller and a digital signal processor, the C28x core brings the code density and execution speed of a DSP with the ease of use and accessibility of a microcontroller. ...Single cycle read-modify-write instructions, single cycle 32-bit multiply. ...32-bit floating-point unit on select controllers...
Enhanced PWM modules offer high resolution (down to 65ps) duty cycle, period, and phase control. Additionally, fully programmable trip zone detection and dead-time generators offer complete system protection from faults and surges. (Does Stella have this?)
***Alan have you been able to determine which is "better" or how key characteristics differ between Stella and Piccollo for motor apps? We know it is out there somewhere in TI space, but I haven't been able to find it. It looks like Hercules is the top dawg, but it is 2x the cost and a larger board as you said. The control card pushes $100 in lieu of $45 ish.