V3 inputmux
Analog Input Multiplexer

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Second serial Analog/Speed Inputs

The second serial Analog/Speed input function allows you to receive 6 additional analog channels via second serial TF stream. Second serial Analog and Input Mux functions are mutually exclusive, you can use either one but not both.

The channels received via serial stream are stored in the following locations:

  • serial Analog 0-5, stored in MUX A1-B3
  • serial Speeds, stored in WheelSpeed 1/2

For proper operation the following minimum software versions are required:

  • ecu firmware 1.2.43 (or higher)
  • VemsTune 1.5.46 (or higher)

Second serial Analog/Speed Inputs settings

Second Serial RX Port Setup

  • Second serial Baud rate: Second serial Baud rate, fill 19200.
  • Second serial Data bits: Second serial Data bits, fill 8.
  • Second serial Stop bits: Second serial Stop bits, fill 1.

Analog Inputs/Speeds via 2nd Serial Setup

  • Store 2nd serial Analogs to MUX channels: Enables serial Analog 0-5 storing to MUX channels A1-B3.
  • Store 2nd serial Speeds to Wspeed 1/2: Enables serial Speeds storing to WheelSpeed 1/2 (overwriting); only enable in applications where Wheelspeed 1/2 trigger inputs on v3 are used for CAM trigger/control.


Analog Input Multiplexer

The analog input multiplexer function with its matching hardware allows you to expand 2 MCP3208 analog input channels to 8 demuxed input channels by time interleaving and multiplexing the sampling of those channels.

The resulting 8 demuxed channels have the following properties:

  • sampling speed is (internally appr 31 Hz) 1/4th of normal sampling speed (internally appr 124 Hz)
  • mux ch A0 is stored in multiplexed channel A selected channel setting location
  • mux ch A1-A3 are stored in MUX A1 to MUX A3
  • mux ch B0 is stored in multiplexed channel B selected channel setting location
  • mux ch B1-B3 are stored in MUX B1 to MUX B3

For proper operation the following minimum software versions are required:

  • ecu firmware 1.2.36 (or higher)
  • VemsTune 1.5.46 (or higher)

Input Multiplexer settings

  • Mux address output facility: The output facility type the mux address lines are connected to.
  • Mux address output channels: The output channels used (on selected facility) take care, these should NOT have ecu internal pull-up.
  • Mux input channel B: The MCP3208 channel connected in mux output B this should be highest number of the two selected channels, without ecu internal pull-up and RC filter.
  • Mux input channel A: The MCP3208 channel connected in mux output A this should be lowest number of the two selected channels, without ecu internal pull-up and RC filter.

NOTE: analog input multiplexer is for advanced users only (new fw required, "analog input raw" might show lower or higher than real: might need calibration in VT for pressure/temperature reading; perhaps with ini-tweaks to show 0-5V for 0-5V input especially if internal pulldown is in effect eg on mcp3208/ch1 ;
For most purposes, the 8 extra analog inputs should be enough. If running low on analog inputs, instead of this inpmux, possible to order with order comment: "all possible analog inputs + third trigger(HALL type) + wheelspeed2": those can be used for ALS/launch activation inputs (free of charge).