Controllers¶

A controller is the transmission control strategy that runs on the device (in
the schema it is called a driver). It turns engine and chassis
inputs into the signals a transmission needs, and exposes
transmission state back through outputs and
CAN presets. Read
Configuration Concepts first — it explains where a
controller sits in the signal flow.

Each controller is selected for the device and then calibrated through its own
set of parameters and maps/tables. The pages below document
one controller per page.

Driver catalogue¶

The configuration app offers these controllers. Which ones are available depends
on the device type (serial-number prefix): a CANbus Gateway (CGW…) and an
IOcan (IOC…) run the gateway and emulation drivers; a GCU (GCU…) runs
the standalone transmission drivers.

The GCU PDK driver controls the 7DT45 gearbox hardware directly (clutch and
line-pressure solenoids, gear actuators) and is not the same thing as the
OEM PDK Gateway, which talks to the car's factory PDK controller. See
OEM PDK Gateway.

OEM gateway drivers¶

The 8HP OEM Gateway and OEM PDK Gateway are the same kind of driver: an
OEM gateway. They let you keep the factory transmission controller (TCU)
and run it behind a standalone/aftermarket ECU. The TCU still does the gear
shifting; the gateway gives it the engine picture it expects.

Aftermarket ECU ─inputs→  OEM Gateway driver  ─CAN preset→  Factory TCU
   (RPM, TPS,             (emulates the engine,            (8HP / PDK
    torque, …)             reports gear state)              mechatronics)
Outputs / dash  ←─────────  gear, mode, speed  ←───────────  TCU state

What the gateway driver does:

• Emulates the engine towards the TCU — most importantly engine torque, plus
  RPM, throttle/pedal, MAP, temperatures and chassis signals. Factory TCUs schedule
  shifts and set clutch/line pressure from the torque signal, which aftermarket ECUs
  rarely broadcast in the OEM format.
• Reports transmission state back to the rest of the car — current/next gear,
  gearbox mode, ratios, shaft speeds, temperature, vehicle speed, reverse light.
• Handles clutchless shifts with the DBW Modifier (torque cut on
  upshift, blip on downshift).

The on-wire conversation with the TCU is implemented by a transmission-emulation
CAN preset (one per platform/generation),
which you pair with the driver — they are listed on each driver page.

Engine torque estimation¶

Because the torque signal matters so much, the driver can obtain it several ways.
The Torque calculation method parameter selects one; the tables it needs are
filled on the driver page.

Drag maps (engine-speed / throttle / MAP) and the lambda-efficiency map correct the
estimate for engine braking and mixture. Not every method needs every table — fill
the ones for the method you choose.

DBW Modifier¶

The DBW (drive-by-wire) Modifier produces clean, fast shifts without lifting by
momentarily overriding the electronic throttle / pedal request:

• Cut (upshift) — pulls the request down to unload the driveline, then ramps
  it back. Calibrated by limit position and ramp-in / ramp-out time tables.
• Blip (downshift) — pushes the request up to match revs, then ramps back.
  Calibrated by target position, time, and ramp-in / ramp-out time tables.

The cut/blip tables are indexed by gear and by load (torque) or rev-match need
(ΔRPM), so the override is sized to the shift. See each driver page for the exact
axes.

Fuel / injector model¶

When torque is derived from fuelling, the driver models each injector set
(primary and optional secondary) with injector size, nominal pressure and a
dead-time table, plus fuel density, stoichiometric AFR and fuel
energy tables so flex-fuel and temperature are accounted for.

How the reference tables are written¶

Each driver page lists its inputs, outputs, parameters and
calibration tables (maps). Names, units, ranges and defaults are taken from the
driver's UI definition in config-studio-data/controllers/*.json; the on-wire
fields and tags come from the matching *.proto message. Map axes, scaling and
interpolation follow Scaling and Maps.

Related¶

• Configuration Concepts — controllers in the signal flow
• Working with the CAN Bus — CAN presets and networks
• Scaling and Maps — how maps/tables are entered and interpolated
• Supported transmissions