V3 inputmux
Analog Input Multiplexer

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Analog Input Multiplexer

The analog input multiplexer function with its matching hardware allows you te 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).