Quantity   Component name
2 × Nameless brushless DC controllers from eBay, which I let the smoke out of http://www.ebay.com/itm/36V-48V-350W-Electric-Bicycle-E-bike-Scooter-Brushless-DC-Motor-Controller/371239291127
1 × Teensy 3.1
2 × "Ming Liang" brushless DC controllers from eBay, which I did *not* let the smoke out of (yet) https://www.ebay.com/itm/36V-48V-350W-E-bike-Scooter-Brushless-Motor-Controller-With-Without-Hall-Sensor/401454355181