In an earlier Blog, I wrote about interfacing Harry's Lap Timer, utilizing the Bluetooth LE interface on the RPi meant for streaming the CAN data of my e46 m3 based car. Recently I have played with a nRF52 chipset to develop a custom CAN to BLE solution for streaming CAN data to Harry's Lap Timer.
Looking into the opportunity to develop a solution that measure brake disk temperatures using a 16x4 pixels IR sensor and which transmits the measurements over Bluetooth LE (BLE).
One of the unique features of my MK60 emulators are to emulate with an mss54/mss54hp in the system, i.e. with only the IKE missing. So far, a requirement has been "mss54 with EWS deleted", since the IKE act as a gateway between the mss54 and the EWS.
Harry's Lap Timer claims to be "the worldwide #1 video and timing app" for car enthusiasts taking their car to the race track. All that is needed is a Smartphone. To fully utilize all the features in the app, an OBDII reader and an external GPS is recommended.
A part of this project has been to develop measurement of the temperature in the rear differential. The temperature is measured by a custom analog2CAN HW using a NTC temperature sensor, and the diff. temperature is streamed onto the CAN bus once a second and visualized in the airVent Display.
At the race track it is of great interest to have some sort of control with the temperature in the gear box. Our solution is to use the analog2CAN HW for gear box oil temperature measurement, which streams the temperature measurements onto the CAN bus for visualization in the airVent Display.
Had to do a few respin of the bezel development in order to optimize for visibility and eliminate reflections in the screen, especially from the rear window during very bright conditions. Happy now...
Finally, the time had come to install the airVent Display in one of my E46. The first installation had to be in the E46 332ti. I'm very happy with the result. The main color codes matches the E46 M3 instrument cluster colors perfectly when it is dark.
The bezel surrounding the display have so far been designed by me. Got some help from a good and very skilled colleague to make the bezel perfect. I'm very pleased with the result...
As said in the previous blog, an important task on the backlog has been to stream the CAN data to the cloud. After testing different providers offering solutions for receiving my CAN data, I realized I had to make my own solution.
An important task on the backlog has been to stream the CAN data to the cloud. It kind of merge all the work with the HW and SW with all the learnings from the Race Engineer Course.
One of the unike characteristics of the airVentDisplay HMI is that it get all its data from the CAN bus. That said, some of the displayed data is taken from the KBUS and streamed to the CAN bus by the KBUS2CAN hardware. With its communication speed limited to 9600 baud, the KBUS is not well suited for high data streaming rates.
Being a bit over the average interested in brakes, brake configurations and testing, I had "Include Stopping distance" as a part of the Performance GUIs on my development backlog.
At the race track there is great information in looking at the difference between the wheel speeds at each axel. The wheel speed information is hence merged into the brake pressure GUI, which already have the instant wheel speeds.
Next up the backlog has been to calibrate the oil pressure sensors and to fine tune the software. A 0-100psi pressure sensor is mounted in an oil distribution block for the M54 solution. For the S54 solution the oil pressure sensor will be mounted directly into the spare M12 location in the oil filter housing.
The display unit used in the airVent Display is a TFT with LED backlight. The backlight can easily be adjusted - manually. However, due to severe light condition variations, manual adjustment is not a practical solution when using the display in an application in a car.
Due to winter time and practical considerations, an E46 325ti has served as a test mule for the test of the airVent Display. Have come so far no that I could not resist the temptation to try it in my E46 M3 based car.
Function testing the Lambda values, IAT and Coolant temperature read from the ECU via the KBUS and redistributed to the CAN bus using our KBUS2CAN solution. The airVent Display picks up the CAN messages and displays the values.
Yet another in-car test done. When running without direct reading of the brake pressure sensors, the brake pressure can be read from the MK60 via the KBUS and redistributed to the CAN bus in a custom CAN message.
Even thoug the screen on the airVent Display is a touch screen, there is also support for using the Cruise Control Buttons on the multifunction steering wheel to control next/previous/home GUI Page on the airVent Display.
Found finally a time slot to test the airVent Display in one of my cars. Had to make a cable harness for easy test of the prototypes before the test could begin.
Had the great pleasure and opportunity to participate at a Race Engineer course. The course was arranged by Norwegian Speed Factory, and the coach was the legendary Michael Zotos.
A KBUS2CAN module had to be made. Not all interesting data is available on the CAN bus. Some data is only aviable via the KBUS and needs to be extracted before retransmitted onto the CAN bus in custom CAN messages.
CAN2HMI controller needed to be developed in order to interface the airVent mounted HMI touch displays.
A video from the latest bench test of the airVent Display is made. The video is found on Vimeo, and the link is airVent Display prototype test.
Analog2CAN modules for reading pressure sensors (0-5V) and temperature sensor (RTD/PTC) are developed.