ODrive: cheap, powerful and hackable motor controller

Hi ! I discover the ODrive thanks to this video performed by this Gentleman.

He is building 3D Printed gears and his current project is building a robot using such gears.

The ODrive looks like this.
It has an ARM microcontroller (STM32), two motor drivers and a real bunch of mosfets to drive two motors and a power resistor.
The board layout gives you an hint that this board is able to handle a lot of power :-)

The specs are the followings:

• 24V and 48V version
• Peak current > 100A, above 30A in continuous it will need some active cooling (https://discourse.odriverobotics.com/t/motor-torque-and-temperature-measurements-for-keda-6364-motors-and-mosfet-temperature-rise/356)
• Encoder (8192 per revolution $ 39)
• Braking mode: regenerative (battery packs) or brake resistor.
• Versatile interfacing: USB, Step/Direction, UART, Servo PWM/PPM, CAN ...
• Cost effective $ 129 for 24V and $ 159 for 48 V
• RC motors are super cheap, very powerful ( $ 15 for 700W ) and they can spin really fast.

GitHub for Hardware and Software: https://github.com/madcowswe/ODrive#getting-started
The firmware seems to use FreeRTOS, STM32 libs.
HackADay: https://hackaday.io/project/11583/logs?sort=newest

There is this excellent spreadsheet that shows a characterization of several RC motors (including voltage, acceleration, braking resistor...)
https://docs.google.com/spreadsheets/d/12vzz7XVEK6YNIOqH0jAz51F5VUpc-lJEs3mmkWP1H4Y/edit#gid=0
Typically for a 3D Printer, the 24V board seems enough for even large printers and common CNC machines (up to 1Nm torque with 1KW motors), above this torque the 48V board is needed.

Video Demos:

• A relatively heavy gantry
  
• An Ultimaker style gantry using probably fish ropes instead of belts
  

This board allows to control high speed/power motors in a closed loop, this enables 3D Printers/CNC/Robots to move in the industrial league: control of the position/speed/acceleration/torque and also silence. The torque and the rpm can be limited at the firmware level, so you do not need large and expensive power supplies.

Pretty cool hardware !