Author Topic: Multiplexer install sanity check  (Read 4259 times)

Offline BigD

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Multiplexer install sanity check
« on: May 04, 2018, 05:10:22 pm »
Hey guys,

I'm getting ready to wire in the multiplexer and I was wondering if you could help verify that I've got it straight.

First off, I have a 3.6 ecu, my analog 0 is not hooked up due to EC18/1 being used for knock, so can I just connect one of the multiplexer output channels directly to that leg of mcp3208? Same with ch3. My Ch1 is not pulled up so I can use that one too (but it's in use so I'd have to move the input to the muxer), the rest are pulled up though so I would need to remove the resistor right?

The next thing I'm not clear on is the input assignment. The paper with the unit says that it turns 2 inputs into 8 (ie +6). The diagram on the top right seems to suggest that the channel you use for A will be on Ach0, and for B on Bch0. But then the table at the bottom says that the default configuration is that they will be on Ach3 and Bch3.... which is it and if there are 4 possibles, how do you change it?

In vemstune, you can't pick demuxed A/B 0, so that to me suggests that it's the first scenario. In other words, I will have the demuxed A/B 1..3 and if I use mcp3208 ch0 and 3 for the multiplexer for instance, then if I pick analog 0 and 3 in vemstune, I'm actually picking demuxed A0 and B0.

Thanks in advance!
« Last Edit: May 04, 2018, 05:12:16 pm by BigD »