2nd RS232 serial is very practical, see "2nd UART" below.

Configure 2nd UART to send "5 byte stream" with datacontent matching the AIM (but currently no wasted gaps)

Requirements

* Newest 1.2.35 firmware (compile time after 2016-07-14)

Configuration (VemsTune checklist)

* VT -> Ecu Calibration:

** iButton anti theft: disabled

** prohibit/iButton2 high byte: 8

** prohibit/iButton2 low byte: 1

* VT ->Ecu Logger -> Ecu Log Settings:

** GPS Log Baud rate: 19200 (actually 2nd serial port baudrate; in old VT if this entry is greyed out => temporarily enable bytestuffing)

** Ecu log use byte stuffed format: disabled

** Automatic GPS Log to SD card on main serial port : disabled

** SD Card Trigger Log: disabled

* VT->Outputs->Display Settings:

** AIM disable => send via 2nd serial if 2nd serial is free (renamed accordingly in VT 2016-07-..)

** AIM enabled => send via 1st serial (as traditionally), respecting the "teletype restriction" (even those receivers should pick it up that do not understand the bytesequence without the wasted gaps)

*** but only when VT -> Ecu Calibration:

*** prohibit/iButton2 high byte: NOT 8 ; make sure this value is NOT 8 (eg. 255 is fine) before enabling AIM

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2nd COM wiring

2nd COM port for live data (FW 1.2.35 and newer), 2nd RS232 3 pin (unpopulated header) towards the main processor:

* GND (easy to locate)

* TX (measures appr -7V when idle)

* RX (input, as an experiment pull to +5V with 1k resistor and it will follow to 3..4V perhaps).

Located above the MAX232D (SOIC16) chip, different header, otherwise the same pinout as the 1st RS232 (which is towards the L293D stepper driver IC). See GenBoard/VerThree/Schematic