Pin E24 SEFMJ - Multiplexer...

K-Series Programmable ECU installation questions / support issues
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MartynL
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Joined: Fri Aug 30, 2013 2:29 am

Pin E24 SEFMJ - Multiplexer...

Post by MartynL »

When enabled for a PRB ECU, what's the output voltage on that? (Sorry - not near my car to meter it!)
Is it 12v?

Looking to hook it up to my Ardiuno board and utilise some of the serial data it outputs. If it's 12v, I'll need a MAX232 IC or something to step down the signal to the 5v that the arduino can handle.

Cheers,
Martyn.
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Spunkster
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Re: Pin E24 SEFMJ - Multiplexer...

Post by Spunkster »

MartynL
Posts: 11
Joined: Fri Aug 30, 2013 2:29 am

Re: Pin E24 SEFMJ - Multiplexer...

Post by MartynL »

You'd think that wouldn't you, having read the help file?

Only.. when I put a multimeter on the output, to gnd, depending on which option that's selected, gives a different voltage output reading - Normal, and the 2 lotus options seem to output 12v, where as the Datalogger (9600 & 19200) gives a ~4.8v reading.

Is this an 'undocumented' feature?

I only ask as I'm playing around with my Arduino board to read the serial data from this output, as per the spec provided. It has all the available parameters parsed out and available to do 'other' things with, to either a CAN Bus compatible Lotus stack, or an external display. I might even replace the dash cluster with a touch screen TFT, enabling me to select what I want to see, depending if I'm on road or track:

Code: Select all

typedef struct {
  byte speed_kph; // kilometers per hour
  unsigned int rpm; // rpm
  byte gear; // 0 - 6
  int ect; // degrees Celsius
  int iat; // degrees Celsius  
  unsigned int battery_voltage;// millivolts
  byte tps; //0% = 0x15, 100% = 0xE5
  unsigned int map_mbar; // mbar
  unsigned int injector_duration;   
  byte ignition_timing; // 0.5 deg
  
  boolean reverse_lockout; // 1 = ON, 0 = OFF
  boolean brake_switch; // 1 = ON, 0 = OFF
  boolean AC_switch; // 1 = ON, 0 = OFF
  boolean AC_clutch; // 1 = ON, 0 = OFF
  boolean SCS; // 1 = ON, 0 = OFF
  boolean EPS; // 1 = ON, 0 = OFF
  boolean Fuel_pump; // 1 = ON, 0 = OFF
  boolean Radiator_fan; // 1 = ON, 0 = OFF
 
  boolean VTEC_oil_pressure; // 1 = ON, 0 = OFF
  boolean VTEC_solenoid_1; // 1 = ON, 0 = OFF
  boolean VTEC_solenoid_2; // 1 = ON, 0 = OFF
  boolean MIL; // 1 = ON, 0 = OFF
  boolean Nitrous_1_arm; // 1 = ON, 0 = OFF
  boolean Nitrous_2_arm; // 1 = ON, 0 = OFF
  boolean Nitrous_1_active; // 1 = ON, 0 = OFF
  boolean Nitrous_2_active; // 1 = ON, 0 = OFF
  
  byte cam_angle;//0.5 deg
  unsigned long lambda; // (0x8000 = 1.00, LSB = 1/0x8000 lambda)
  unsigned int knock_count; // knocks since power on, LSB = 1 knock
}
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Hondata
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Re: Pin E24 SEFMJ - Multiplexer...

Post by Hondata »

You can't use a multimeter to measure a digital signal. Its showing the average of the waveform, which is not useful information to man nor beast.
Hondata
Zuby
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Joined: Thu Jan 07, 2016 2:03 am

Re: Pin E24 SEFMJ - Multiplexer...

Post by Zuby »

I realize this topic is old.

I'm attempting to do something similar, output serial data through an Arduino onto an LCD to use as an instrument cluster.

MartynL, would you mind sharing any code that's worked out for you in terms of reading the serial data.

Thanks!
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