k-line arduino project, speed and brake lights

Projects General Guidance
1

Hello.

I have a simple task to achieve, I guess, but I'm stuck. I'm using the setup from the attached image. All I need to do is to read the Speed of the vehicle using data from the obd2 k-line pin, and then to send a command to blink the brake lights when a certain decrease in speed is detected (e.g. more than 2km/h/s). I can not initialize the k-line and I am not able to red anything on the serial monitor on arduino :(. After I manage to read the raw data I am planing to figure out what's the code for turning on the brake lights by just simply pressing the brake pedal. The vehicle is an 2004 BMW E60, but I guess this is not an issue.

Question... Are the TX/RX pins connected as it shod on the arduino board?

Thank you. Ant help would be appreciated. I need this for a school project and a have a deadline :(((

k-line arduino.png
k-line arduino.png492×575 135 KB

1 Like
2

I can not initialize the k-line and I am not able to red anything on the serial monitor on arduino

You can have only one thing connected to the hardware serial port (pins 0 and 1) so you can't read and write to the interface chip and the serial monitor at the same time on the same port. The Arduino Mega has 3 hardware serial ports so may be a better board for your project.

There are software serial libraries for the Uno, but I don't know if they are fast enough.

3

look at the red wire in your drawing and see if you can tell if anything is amiss...

4

Hello.

I have a simple task to achieve, I guess, but I'm stuck. I'm using the setup from the attached image. All I need to do is to read the Speed of the vehicle using data from the obd2 k-line pin, and then to send a command to blink the brake lights when a certain decrease in speed is detected (e.g. more than 2km/h/s). I can not initialize the k-line and I am not able to red anything on the serial monitor on arduino :(. After I manage to read the raw data I am planing to figure out what's the code for turning on the brake lights by just simply pressing the brake pedal. The vehicle is an 2004 BMW E60, but I guess this is not an issue.

Question... Are the TX/RX pins connected as it shod on the arduino board?

Thank you. Ant help would be appreciated. I need this for a school project and a have a deadline :(((

k-line arduino.png
k-line arduino.png492×575 135 KB

5

catasbox:
Hello.

I have a simple task to achieve, I guess, but I'm stuck. I'm using the setup from the attached image. All I need to do is to read the Speed of the vehicle using data from the obd2 k-line pin, and then to send a command to blink the brake lights when a certain decrease in speed is detected (e.g. more than 2km/h/s). I can not initialize the k-line and I am not able to red anything on the serial monitor on arduino :(. After I manage to read the raw data I am planing to figure out what's the code for turning on the brake lights by just simply pressing the brake pedal. The vehicle is an 2004 BMW E60, but I guess this is not an issue.

Question... Are the TX/RX pins connected as it shod on the arduino board?

Thank you. Ant help would be appreciated. I need this for a school project and a have a deadline :(((

RX K-line -----> TX Arduino
TX K-line -----> RX Arduino

6

123Splat:
look at the red wire in your drawing and see if you can tell if anything is amiss...

Yeah... ignore that red line... it's not connected.

7

@catasbox, stop hijacking.

@catasbox, stop cross-posting.