Arduino-powered digital dashboards... For kittens!

This is designed to receive data over CAN BUS from a MegaSquirt and present it on a Nextion LCD display.

It also allows you to use the Arduino's analog-in pins as extra analog inputs for the MegaSquirt.

This software is designed for:

• Arduino Uno
• Seeed Studio CAN-BUS shield v1.2
• Nextion NX4024T032_011R display
• Arduino IDE 1.6.6
• MCP_CAN_lib
• MegaSquirt III, firmware 1.4.0

These exact versions are known good, but other variants probably work.

This depends on MCP_CAN_lib to communicate with the CAN BUS chip. To install it on Linux:

cd ~/Arduino
git clone https://github.com/coryjfowler/MCP_CAN_lib.git
cd MCP_CAN_lib
git checkout eecf231fb0b1e594086f6212dfd6b643eca1b8d9

Now start the Arduino IDE and open dash-kitten.ino; click Upload and it should build and run.

Plan A:

• Connect the display to a TTL-serial cable
• Open dash-kitten.hmi in the Nextion GUI
• click upload
• If the transfer fails your display may be bricked. Proceed to Plan B.

Plan B:

• Copy dash-kitten.tft as the only file on a FAT32-formatted micro-SD card
• Click it into the SD slot
• Power on
• Find out that the Nextion display is really picky about which SD cards work
• Find another micro-SD card
• GOTO 10

Stack the CAN-BUS shield on the Arduino, and connect the CAN-high and CAN-low pins to your MS3.

Connect the Nextion display as follows:

• Black - GND
• Red - 5v
• Yellow - Digital pin 4
• Blue - Digital pin 5

To send data from the MegaSquirt to the DashKitten, go to CAN-bus/Testmodes, then CAN Realtime Data Broadcasting 1/2/3/4. We're using these settings:

To send analog measurements from the DashKitten to the MegaSquirt, go to CAN-bus/Testmodes, then CAN Receiving. Configure the channels to be:

There appears to be a bug in MegaSquirt v1.4.0: If the sensor's value exceeds 3276 it will be corrupted. This appears to be a bug in the MS firmware where values are being multiplied by 10 internally (probably fixed-decimal), and being handled as signed values even though they shouldn't. The Arduino Uno's ADC will only output 0-1023 so if you use Multiply=1 Divide=1 it will be fine. Multiply=3 Divide=1 will still be fine (max 3069), but Multiply=4 Divide=1 will cause an overflow into negative numbers. I haven't tried, but Some other models of Arduino such as the Zero have a 12-bit ADC and may have problems even with Multiply=1.

Next go to Advanced Engine, then Generic Sensor Inputs, and assign the CAN ADCs to generic sensors:

You can configure the Field Name to be anything, such as "Oil Pressure". This is what will show up in the logs.

GPL v2