Sparkdog PF-DI Extension The Sparkdog PF-DI extension including Teensy 3.5 is an optional PCB that can take the place of Arduino Due, mounting on to the Rabbit ECU. The picture above shows a Sparkdog PF only board, which accepts the Teensy 3.5 but does not have the GDI circuit populated. When plugged into the Rabbit ECU, this provides a powerful DIY ECU with an additional 2 saturated injector drivers, DBW throttle control, a powerful peak hold driver that can be used for TBI, and 4 VVT signal inputs. These drivers are in addition to the 4 saturated injector drivers, 4 ignition/general purpose push-pull drive signals, 8 relay outputs, 8 analog inputs and CAN bus provided by the Rabbit ECU PCB. Teensy 3.5 The Teensy 3.5 controller takes place of the Arduino Due. The ECUHost port provides 18 timers as well as 10 analog inputs, CAN bus, USB connection, plenty of additional I/O over SPI and 120 MHz clock speed. Co-processor The MK10 provides an independent controller for the DBW control, as well as knock sensing inputs. A serial link allows communications between the Teensy MK64 processor and the co-processor. Schematics Schematics for Sparkdog PF extension. Code Firmware updates are coming soon. The firmware is available as a downloadable hex image that can be loaded into the Teensy 3.5 with free tools. To update the co-processor firmware you will need a debugger such as PE Micro Multilink.