ISkewB Industrial Servo Brick
Gotta love marketing eh? Really I just needed a name to refer to in other projects.
This will be an integrated motor module - motor, sensors, power electronics and data acquisition, all housed in a compact, rugged, waterproof heatsink/enclosure. Plug it in and go! Target budget is $40 each.. damn that makes it sound expensive :( It actually is turning out to be quite a challenge to get it that low..
The initial revision will use an attiny13 to PWM an h-bridgeand simultaneously count encoder pulses, talk SPI via cat5 cable with a motherchip, and read/write i/o for limit switches and whatever else. (thermistor? cooling fans?)
RJ45 interface pinout
5V
GND
SS
SCK
MISO
MOSI
Fault (open collector-ish)
GND
SS
SCK
MISO
MOSI
Fault (open collector-ish)
Parts list:
- h-bridge
- power stage
- 127K9720
- servo motor
- pcb mount RJ45 jack
- top entry Jameco P/N 524488 $0.39 each min qty 10
- OR
- pcb mount RJ45 jack side entry low profile Jameco P/N 524461 $0.55 ea min qty 10
- OR
- ES1607 shielded PCB mount RJ45 jack from excesssolutions.com $0.25 each min qty ??
- cable assembly,cat 5e,3ft
- jameco p/n 523021, $1.33 ea min qty 2
- Standard Opto-interrupter, fork style, qty 2
- forhome and index pulse goldmine-elec.com p/n GP44, $0.14 ea min qty 18 (or so) (i know bad choice of components, i'll find something on jameco or digikey later, something like Jameco P/N 114091)
- thermistor
- goldmine-elec.com p/n G14610, $0.33 ea, min qty 3
encoder read board:
- attiny13
- cheap powerful microcontroller to read encoder signals and PWM the h-bridge
- CAP,RADIAL,33uF,50V, 5mm x 11mm
- power filter for attiny13, Jameco p/n 93745PS, $0.05 ea min qty 10
- CAP,CERM,DISC,.1uF,50V
- power filter for attiny13, Jameco p/n 15270, $0.15 ea min qty 10
- cd-rom audio connector
- for connecting the encoder lines, maybe this should go in iskewb..Jameco P/N 100802CK $0.25 min qty 10, and jameco p/n 152733CK (maybe?) $0.45 (need pins too) jameco p/n 181673 another $0.44 each. also maybe molex 50-57-9004 would work, it can be obtained from digikey.
