Validation

It is common for the CAN-Bus to display incorrect information (reference Example of Bad Output #1-3, below).  The data is not incorrect, rather it is being displayed incorrectly.  For example, if you tell the CAN-Bus to retrieve data for Engine RPM, it may instead retrieve data from the MAF Sensor.  I am not sure if this is a flaw of CAN-Bus communication or a sign of limitation in the hardware being used.  I found that although the CAN-Bus occasionally retrieves incorrect information.  The frequency of this error can be reduced by:

A)      Reducing the amount of information being called for.  If you call for all vehicle diagnostic data at the same time, the information will surely be presented incorrectly.  If instead you only call for one piece of vehicle diagnostics, such as Engine RPM, then you will see less errors in the output data.  Reference Example of Bad Output #1, below.

B)      Calling for data several times before printing it.  If you call for Engine RPM data once, it has a chance of being incorrect and printing other data like Speed.  If you call for Engine RPM data ten times per second and only print Engine RPM data once every second, then you call for it ten times before printing it once.  By having a high ratio (times called : times printed), you decrease the frequency of printing incorrect data.  Reference Example of Bad Output #3, below.

EXAMPLE OF BAD OUTPUT #1:

Vehicle Speed: 0 V

Engine RPM: 0 V

Throttle: 701 rpm

Engine Coolant Temp: 701 rpm

O2 Voltage: 701 rpm

MAF Sensor:  701 rpm

EXAMPLE OF BAD OUTPUT #2:

Vehicle Speed:  N/A

Vehicle Speed:  N/A

Vehicle Speed:  0 km / hr

Engine RPM:  N/A

Engine RPM:  N/A

Engine RPM:  678 rpm

Throttle: 690 rpm

Throttle: 0 V

Throttle: 12 %

Engine Coolant Temp: 0 V

Engine Coolant Temp: -36 degC

Engine Coolant Temp: 85 degC

O2 Voltage: 0 V

MAF Sensor: 0 V

EXAMPLE OF BAD OUTPUT #3:

Vehicle Speed: N/A

Vehicle Speed: 0 km

Vehicle Speed: 0 km

Vehicle Speed: 670 km

Vehicle Speed: 670 km

Engine RPM: 0 km

Engine RPM: 0 km

Engine RPM: 701 rpm

Engine RPM: 701 rpm

Throttle: 693 rpm

Throttle: 693 rpm

Throttle: 12 %

Throttle: 12 %

Engine Coolant Temp: 12 %

Engine Coolant Temp: 87 degC

Engine Coolant Temp: 87 degC

O2 Voltage: 87 degC

O2 Voltage: 87 degC

O2 Voltage: 87 degC

O2 Voltage: 87 degC

MAF Sensor: 87 degC

MAF Sensor: 87 degC

MAF Sensor: 87 degC

MAF Sensor: 87 degC

MAF Sensor: 1 g/s

MAF Sensor: 1 g/s

MAF Sensor: 2 g/s

MAF Sensor: 2 g/s

NOTE:  There may be some fundamental limitations of the CAN-Bus exchange OR the computer’s capacity to process data.  Since data can slow at two locations (vehicle to Arduino and Arduino to computer) lets focus on one hurdle at a time.

I originally had a video on this slide.  But the video was too large to send via email.  The video

demonstrated my ability to gather real-time vehicle data and project it onto the App that I created.

If the engine is running, oil maintenance required, ABS active, AC control status, driver is breaking, parking break is on, cruise control, lights are on, turn signal is on, airbags are on, vehicle is in sports mode, gear position, pedal position %

wheel speed → this can be used to identify which tire is flow on air pressure

If the engine is running, If oil maintenance is required, if driver is breaking, if the parking break is on, if cruise control is on, if lights are on, if turn signal is on, if airbags are on, if vehicle is in sport mode, gear position, pedal position %, AC and temp control status, Alerts – maintenance, oil required, ABS active