There is no 'official' solution for outputs yet. My best answer for the combination of HC and LC outputs, is that:
- Idle, VVT, and Boost should be on HC outputs for direct-drive of the devices by PWM.
- Other outputs (Fan, Fuel Pump and TachOut) can be either HC or LC, to external relay or direct (TachOut).
- LC outputs from Mega D43 to D51 require a clamped driver of some kind, such as transistor with diode, ULN2803, or similar to drive a relay.
- All outputs except Idle are assignable in TS.
As for what to do about the LC output drivers, either discreet transistors/FETs of some suitable kind, or the ULN2803 type can be installed in the 'proto' area. If using the ULN2803 as listed in the v.04 BOM, it can be installed with ULN leg 9 in PCB GND on the board and up across the D51 to D43 outputs for the ULN inputs. Cut ULN leg 8 if A15 might be used on Speeduino. I would just cut it.
Lift ULN leg 10 and solder a wire from the leg to raw (Vbat) 12V+ on J3 or other raw 12V+ point such as U2, C16, C15, or JP1. Diagonally across the board would probably
be best to minimize induction of noise. DO NOT allow ULN pin 10 to touch any part of the board except the wire connection to +12V!
Either spread the ULN legs to reach the points to connect to the IDC 40-pin outputs on IDC pins 14 through 18, or bridge the connections on the board. Select the LC outputs active on D51 to D43 in TunerStudio as-required (or reassign LC and HC pinouts
), and verify no conflicts with other outputs designated. Note: due to protection diodes in the ULN, the tachometer output is OK for 5V or 12V triggering with a pullup, but not flyback pulses ("relay coil"
method) as the diode shorts the pulse voltage. Good luck!