ARM based Unidentified Fueling Object - developer info!
The primary application for this board has changed as a result of the ArmEfi growing out of the EC36 connector and the box. The ArmUfo will use the 120X40X2.5mm box and the EC36 connector instead, while the ArmEfi is postponed until we find suitable connector and box.
This board is meant to be the right size for most cars in a standalone application and also scale well when used as a building block in a larger system.
Specification:
Box: Aluminium profile 120X40X2.5mm
Connector: AMP Econoseal III 36 pin.
Internal MAP: Yes, 4bar sensor and 5x3mm pneumatic connector on frontplate. The new small helper board can be used (a sensor with horizontal nipple has better space usage and connection to the frontplate)
CAN: Yes, 1 internal and 1 on EC36 combined with VEMS link.
WBo2: Yes, 1 channel with PNP capability. (although using RCal is really meaningless for an ECM that has 100+ settings anyway and only ment for professional install: RCal just wastes a pin. RCal only makes sense for a standalone meter that can be used by low-qualified servicemen and possibly sensor is swapped a lot when used for testing the sensor itself).
Ignition power stages: Yes, 2. Both can be configured for low voltage flyback (in HW => population time or soldering) if external power stages are used. Current limiting for protection of coils when engine stalls is mostly a software issue 1..3 points on GND5 is measured by ADC so overcurrent or forgotten GND5 is recognized before ECM damage.
Injector outputs: 6, high or low impendance with switched flyback. How do we protect against short circuit?
Trigger: 1VR/Hall channel and 1 Hall only Note, no VR chip. VR analysis made in software after beeing sampled with ADC
Basic sensors: IAT, CLT, TPS.
Pushpull outputs: 4 or 8 (using 1 or 2 SN754410 powerdip). The only task these are most useful for is bipolar stepper (usually only found as idle actuator).
Important: flyback-equipped low-side switch is more useful for:
- injector
- fuelpump relay
- boost solenoid
- variable cam timing
- variable intake
- unipolar stepper (the exceptional case where high voltage flyback is better)
- tachometer output (pullup might be needed)
note: we don't want to drive external ignition modules (eg.: 12 push-pull stepper outputs for an 8cyl engine with bipolar stepper would be stupid), except our CDI / ION
VemsLink: Yes (VEMS link is a high speed CAN and two open collector trigger signals that can be configured as input or output.)
Description of old ArmUfo, move functionality to other board if it doesn't work together with the new specification above.
This is a relatively simple, cheap, minimalistic board, slightly below GenBoard/VerThree functionality, somewhere above (not yet existing) ultramegasquirt complexity.
Main idea is to cover mass-applications (that require only simple installation instructions and configuration) with unbeatable cost.
A similar, but more powerful board is VemsFrontier/ArmEfi - make sure to study that deeply.
- max 1 LM 1815 VR interface + 1 square wave input.
- Internal MAP sensor ? Yes very important -Jörgen
- CLT, IAT and TPS sensors.
- 6 DPAK FET/IGBT's with optional simple hole mount flyback. Used for IGN and INJ. HighZ or LowZ capable. Throughole/SMD issue below
- 1 Bosch LSU Wbo2 sensor controller
- just 1 L293 Stepper driver IC's configured as 4 push pull outputs or as a stepper driver. Can be used to trig up to 4 external ignition modules.
- just 1 CAN bus
- max 2*Knock sensor input (ARM-processed), definitely no TPIC8101
- NO EC36 connector (flying loom is OK)
- 1 EGT input (eg. with AD597AR)
- PS2 and LCD connection planned-in
- 6 buttons for IO interface.
Cost of last 2 must be evaluated during routing. There is a little wrestling going on here :-)
It seems that UI must be a separate board, sized to fit in 120x40 that can be mounted remotely (connected via some sort of serial or CAN) or mounted as endplate.
Notes:
I think that 6 open collector drivers is enough, all of them can be ign capable since we use flying lead. It takes up very little board space. The multi channel ignition capabilities opens up ignition expander & ignition driver applications.
Avoid unnecessary throughole parts, like flyback diodes
- no need for messing with the flyback configuration: this is proven since the injectoropening model had been written
- soldering SMB diodes is very easy
- no need for soldering by the end-user, as we can make it for him if he wants
- this is not ment to be a profitless board for tweakers (and experimenters, that the v3.x is) but a highly standardized (still quite capable) ECM that is selled with profit and supported relatively easily
However, flyback can be throughole if 3A (BY399) continuous current capability is needed instead of 2A (ES2J SMB) or if it saves PCB real estate.
Case relevant issues
It is very important to have IO buttons (how many?) on the box, having a keyboard in the car at all times is not practical. This also makes it possible to make a compact hand held tuner that can tune the ArmEfi and other VEMS frontier products. I guess it is the question of a free digital or analog input(s), and the rest is mechanical (case) issue.
MMC slot ?
- I think the MMC can live inside, without the possibility of removing (maybe soldered)
- anyone insisting on removable MMC slot ?
This (armufo??) is a multi application board, it can be used for the following applications:
With (external ?) display and buttons:
- MAF replacement / MAF tuner.
- WBo2 Lambda meter (? why would someone use this instead of a standalone? maybe this is ment logger box with internal WBO2 controller )
- Boost controller.
- Exhaust temp meter.
- Additional fuel controller.
- Handheld tuner for ArmEfi and the other CAN enabled boards. I highly doubt that this would work. A logger and control board can be merged reasonably. A UI (user-interface) board cannot. (well, apexi makes profit from boost controllers made this way, but separated UI and controller is remarkably better).
- Entry level engine management system with integrated display (how?) and user interface.
Would the display be mounted at the endplate (the opposite side as the EC36?)
Sealed box without display:
- Ignition expander & ignition module. (without display)
- EMS with flashed (what does this mean?) calibration or for use with handheld tuner.
See also
- VemsFrontier/Boards is the family where this belongs