While there are many analog inputs (that can also be used for GenBoard/UnderDevelopment/DigitalInputs of coruse), the pinout has not been standardized yet.
proposal for extra ADC input channels
EC18 beware that these inputs are unbuffered and unfiltered, care must be taken to avoid damage to the MCP3208.
- EC18pin12 direct to MCP3208pin8 (ch7) (standard for secondary_trigger=HALL)
- EC18pin6 direct to MCP3208pin7 (ch6) (standard for internal MAP sensor)
- EC18pin16 direct to MCP3208pin6 (ch5)
DSUB9 male on endplate.
Unfortunately both genders are used: DSUB9 female used for RS232 and DSUB9 male used for LCD. When an ECM has DSUB9 male for both LCD and extra inputs, care is needed at hookup.
- DSUB9pin1 suggestions ? MCP3208pin4 (ch3) direct could be an option, if only 1 EGT is onboard.
- GND might be a good idea as well
- DSUB9pin2 Voltout - negative
- DSUB9pin3 MCP3208pin3 (ch2) - negative
- DSUB9pin4 MCP3208pin2 (ch1) - negative
- DSUB9pin5 MCP3208pin1 (ch0) - negative
- DSUB9pin6 Voltout - positive
- DSUB9pin7 MCP3208pin3 (ch2) + positive
- DSUB9pin8 MCP3208pin2 (ch1) + positive
- DSUB9pin9 MCP3208pin1 (ch0) + positive
The internal HW
The midopa provides 3 nice features:
- protection
- filtering
- differential inputs
- MPC3208pin1
- C42=220nF
- R100=R97=Rinput
- R66=R101=Rmid
- R67=R68=Rfb
- R150=Rout
Values for different amplification:
- buffering (*0.99, measured in one example case: 945mV output / 951mV input). Input range is appr 5V.
- Rinput=100k
- Rmid=1k
- Rfb=100k
- Rout=10k
- x17.5: input range is appr 285mV (this is the minimum recommended when used for extra K-type thermocouple EGT input, if the onboard 2 is not enough)
- Rinput=4k7
- Rmid=1k
- Rfb=100k
- Rout=10k