Eric S Posted October 29, 2020 Report Share Posted October 29, 2020 Can the input threshold of a digital input can be increased slightly? If it's fixed threshold, at what voltage will the input go 0 to 1? and the hysteresis if there is any? My MX5's AC blower fan knob is essentially a voltage divider and ECU only recognises fan speed 1 as HIGH and rest of speeds 2, 3 and 4 as LOW. So the AC clutch will only work when fan speed knob is turned to 1. Did some scoping, attached for future visitors. Since I'm making a custom adapter board for the "main" PCB, I can include some additional comparators with increased threshold (say 4V). I wanted to check if PCLink allows changing the input threshold; I vaguely recall Motec having the ability to adjust it but it's been long time. Cheers Quote Link to comment Share on other sites More sharing options...
Vaughan Posted October 29, 2020 Report Share Posted October 29, 2020 If you want it to switch at a specific voltage you can wire it up to an analog input and setup a virtual aux based on that analog value. Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 29, 2020 Report Share Posted October 29, 2020 Another trick we use on some of the plug-in ECUs is put a diode or two inline on the DI. With a standard diode you will get a 0.7V drop over the diode - so it would lower your 2Vmin to 1.3V. If you connect two diodes in series your 2V min would drop to 0.6V. Quote Link to comment Share on other sites More sharing options...
Eric S Posted October 31, 2020 Author Report Share Posted October 31, 2020 Ah I thought of wiring it into one of spare AV input, but it made me think because whenever blower fan in off position, 10-12V is applied to the input. Since I don't know the input range/limits of AV input, and the maximum allowable error low/high value that can be entered on PCLink is 5V, I assumed the limit is 5V. Can the voltage applied to AV input be read above 10V continuously? If so I'll go with this method otherwise Adamw's series-ed diode method might be the easiest solution. Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 31, 2020 Report Share Posted October 31, 2020 12V is fine to input into an analog input. Just they can only measure to 5V, so anything above 5V will just show as 5V. When the error high is set to 5.0V the fault detection is disabled. Quote Link to comment Share on other sites More sharing options...
Eric S Posted October 31, 2020 Author Report Share Posted October 31, 2020 Ah got it, good to know! I'll wire in to one of AV pin. Cheers. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.