Arduino OBDII Bluetooth Car Engine RPM Shift Light

Discussion in 'The Projects Forum' started by kostaskokoras, Jul 17, 2013.

  1. kostaskokoras

    Thread Starter New Member

    Nov 10, 2012

    It 's about an Arduino project connected to an ELM-327 OBDII Bluetooth through a HC-05 bluetooth module.
    The HC-05 is connected to Arduino with serial UART, and is configured (with AT commands) as Master to connect to ELM-327 OBDII Bluetooth which is the slave.
    As soon as connection established begins the initialitation (with AT commands) of ELM-327.
    After that we can read Engine RPM from car's ECU.
    Next just display the RPM to 7-segment LEDS.
    Shift Lights going ON at the RPM that we configure pressing the button at desired Engine RPM, value is stored to EEPROM.
    Please feel free to comment or suggest or contact me.
    Code is here, schematics will post as soon as possible.

  2. Rbeckett


    Sep 3, 2010
    Car stuff is off limits Kostas. The mods will be by in a bit to close this thread, sorry.

  3. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    Neat project, since it doesn't modify a car in any way but instead just reads the OBDII data I can't see why it would violate forum rules.
    kostaskokoras likes this.
  4. t06afre

    AAC Fanatic!

    May 11, 2009
    Every modern car has an OBDII connector for diagnostics located close to the dashboard. I also would not consider this automotive modification more than plugging in some equipment in the car cigarette lighter connector.
    kostaskokoras likes this.