{"id":391,"date":"2015-06-24T19:53:43","date_gmt":"2015-06-24T23:53:43","guid":{"rendered":"http:\/\/projectsofdan.com\/?p=391"},"modified":"2015-06-24T19:55:28","modified_gmt":"2015-06-24T23:55:28","slug":"digital-dashboard-update-on-factory-sensors-and-pinouts","status":"publish","type":"post","link":"https:\/\/projectsofdan.com\/?p=391","title":{"rendered":"Digital Dashboard: Factory Sensors and Pinouts"},"content":{"rendered":"

Here is a summary of the connections I made to the factory E36 sensors.<\/p>\n

RPM<\/strong><\/p>\n

The RPM signal is a clean 12V pulse train who’s frequency is proportional to the engine speed. If you setup a rising edge interrupt and a timer, it is easy to measure the signal’s period. Be sure to scale the 12V appropriately for your devices I\/O levels. It gives one pulse per cylinder fire and there are three pulses per rotation so the equation boils down to:<\/p>\n

So RPM = MeasuredPeriod(micros) \/ 20000000(micros)<\/p>\n

The RPM signal can be found at three fairly convenient locations that I know of. The wire is always solid black:<\/p>\n

    \n
  1. Pin 1 on the round diagnostic connector under the hood on the passenger side<\/li>\n
  2. Pin 20 on connector X16 to the back of the gauge cluster<\/li>\n
  3. Pin 8 on connector X22 to the cruise control module behind the glove box<\/li>\n<\/ol>\n

    Speed<\/strong><\/p>\n

    The Speed signal is also a clean 12V pulse train who’s frequency is proportional to the vehicle’s speed. Be sure to scale the 12V appropriately for your devices I\/O levels. The sensor is in the rear differential and outputs 9 pulses per revolution.<\/p>\n

    Speed = 6313.13 * TireCircumference \/ MeasuredPeriod(micros)<\/p>\n

    The Speed signal is black with a white stripe and can be found on:<\/p>\n

      \n
    1. Pin 2? on connector X16 to the back of the gauge cluster<\/li>\n
    2. Pin 10 on connector X22 on the cruise control module behind the glove box<\/li>\n
    3. Pin 10 on radio connector<\/li>\n<\/ol>\n

      Throttle Position<\/strong><\/p>\n

      The TPS signal comes form a potentiometer mounted on the throttle body. It’s middle pin\/wire outputs 0-5V proportional to the throttle position. Note that there is about a half a volt of deadband on both ends resulting in an effective range of about 0.5V to 4.5V. I ran this into an ADC and scaled to provide a percentage.<\/p>\n

       <\/p>\n","protected":false},"excerpt":{"rendered":"

      Here is a summary of the connections I made to the factory E36 sensors. RPM The RPM signal is a clean 12V pulse train who’s frequency is proportional to the engine speed. If you setup a rising edge interrupt and a timer, it is easy to measure the signal’s period. Be sure to scale the […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,16],"tags":[29,30,31,32],"class_list":["post-391","post","type-post","status-publish","format-standard","hentry","category-digital-dashboard-electronics-robotics","category-project-m3","tag-bmw","tag-e36","tag-rpm-signal","tag-speed-signal"],"_links":{"self":[{"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/posts\/391","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=391"}],"version-history":[{"count":3,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/posts\/391\/revisions"}],"predecessor-version":[{"id":394,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=\/wp\/v2\/posts\/391\/revisions\/394"}],"wp:attachment":[{"href":"https:\/\/projectsofdan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/projectsofdan.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}