Welcome to NielsenRacing!
I've been looking around a while for a good aftermarket EMS. Getting to know MembersPage/SimonMarmander, who has tested three different EMS' on his car and finally dialing it in with the GenBoard led me to VEMS. After seeing the many uses and possibilities it has first hand, I just had to buy a v3.3 for myself. The number of sensor inputs is one of them. MembersPage/EmilLarsson helped me over the phone so I managed to find the 9 free ADC's. Thanks!
This means lots of sensors, so the ECU will sens everything that happens; to control or prevent. Nice, perhaps I won't blow as many engines in the future as in the past, and if I do, at least I can log it and se why it happened. =)
The car:
- 1975 Volvo 242 Turbo
Engine:
- B23 block borred and stroked to 2.8L, 16V head, custom intake with slide throttle, NOS Pro Fogger system, Holset HX52 turbo, dry sump oil system, closed crankcase ventilation
My VEMS-setup for the B23/16V will be as follows:
Sensor inputs:
ATMEGA 128:
- ADC0: Battery Voltage Sensing
- ADC1: WBO2 #1
- ADC2: TPS
- ADC3: CLT
- ADC4: MAT #1
- ADC5: MAP #1 (In Intake Runners)
- ADC6: MAP #2 (In Plenum)
- ADC7: MAF
MCP3208:
- CH1: Fuel Pressure #1 (Primary Injector Fuel rail @ Intake Ports)
- CH2: Fuel Pressure #2 (Secondary Injector Fuel rail @ Plenum)
- CH3: Fuel Pressure #3 (NOS)
- CH4: Oil pressure
- CH5: EGT #1
- CH6: Backpressure #1 (In Header Collector)
- CH7: Backpressure #2 (In Down pipe @ WBO2 #1)
- CH8: Crankcase Pressure
DIGITAL:
- VR #1 (Crank Trigger)
- VR #2 (Cam Sync)
- Knock #1
- Knock #2
Outputs:
- Coil-On-Plug 1,2,3,4
- Primary Injectors 1,2,3,4
- Secondary Injectors 1,2,3,4
- Boost Control (PWM)
- Fuel Pump Relays (or PWM)
- Electrical Water Pump Control (PWM)
- NOS Solenoid Activation (RPM Window Switch IF @ WOT)
- Cooling Fan Low Speed Relay
- Cooling Fan High Speed Relay
- LED Shift Light Control
You have many extra sensors.
I guess you want to use MCP3208 channels to capture them. To build input protection and RC lowpass filters, a similar circuit is used:
- R1 = 10k resistor and
- R2 = 220nF capacitor (not resistor, as on the schematic)
- instead of the soundcard, the MCP3208 input pins used (pin1..8)
- input goes to the node marked EC36pin27
If we put a few RC filters on a small breakoff-board in our next PCB-batch, we'll apply BAV99 diodes too, for extra protection.
Note: brought here from email, since I only answer technical questions in wiki. Even if the result will be a webshop order (when asking for prices/shipping/billing, point to relevant page when appropriate).
- 1x220nF, in same function as "C49"
- 1x10k in same function as "R126"
- 1xBAV99 "D40" SOT23 BAV99 double ("CACA") diode (marked A7)
- 1x78L05 SOT89 regulator "U27" I doubt that you need this
- I guess I will need one more 78L05 to feed the extra sensors as 80mA is not enough for all of them?
- what exactly do you want to power ? Any specific external circuitry in mind? The pullup resistor of resistive sensor (NTC type temperature or oil pressure pressure sensor) only draws <2mA so we already have plenty of power.
- also note that any 5V on the board can be used to clamp the input (instead of adding an extra 78L05), see
- 5V on the 4-pin PS2 header (pin closest to boardedge)
- or the LCD header 5V
- EC36pin28 (HALL suplpy +5V)
To add to the order, just copy the above to the order note. +0 Euro. Actually, you already have R and C in GenBoard/VerThree/RescueKit.
Connector pinout
- I guess you use an endplate mounted DSUB25 for the many extra sensor inputs (right ?) If so, the small (16x45mm?) filter PCB could be designed to mount on the DSUB25, in edgestyle.
- No DSUB25, I will use automotive multi-pin connectors I got from work..
Feedback and comments are welcome!
Christian Nielsen
Bollebygd, SWEDEN