OBD MPGuino gauge

[tangomar]

Trebuchet03,

if you still have problems, try bugging the developer of JDash (Main Page - JDash). He got it working with ELM323.

[KJSatz]

Was someone trying to make an OBDuino that does CAN without the ELM? Is it showing any promise?

[Magister]

Originally Posted by KJSatz

Was someone trying to make an OBDuino that does CAN without the ELM? Is it showing any promise?

I am, the code is ready, I am waiting for the Microchip MCP2515 from Mouser...

[tangomar]

Any schematics/layout files for the OBDuino?
I was thinking to modify the MPGuino ones.

[KJSatz]

Ooh cool! May your microchip have great success! Keep us posted and thanks for all the work you're putting into this project.

[Magister]

Originally Posted by tangomar

Any schematics/layout files for the OBDuino?
I was thinking to modify the MPGuino ones.

The OBDuino was based on the MPGuino, the basic hardware (arduino, LCD, buttons) are the same in the same place. In the MPGuino there is a VSS input and Injector input, and on the OBDuino there is the ISO input/output (for ISO) or it uses the TX/RX serial port (pin 0/1) for the ELM version.

You can take the MPGuino schematic available here: http://spiffie.org/kits/mpguino/more.shtml and modify it with the Eagle CAD software.

Note: the version with the MCP2515 will have some difference in the pinout of the LCD because of how the MCP interface with the AtMega via SPI.

[knuckles904]

I am eagerly awaiting the CAN only microchip solution. I did have idea on how to control the brightness of the lcd (bright during day, dim during night) pretty easily. Just use a photoresistor mounted on the top of the whatever case you use and have it sample every so often. It seems like there should be tons of analog inputs left and the code should be small.

[Magister]

Originally Posted by knuckles904

I am eagerly awaiting the CAN only microchip solution. I did have idea on how to control the brightness of the lcd (bright during day, dim during night) pretty easily. Just use a photoresistor mounted on the top of the whatever case you use and have it sample every so often. It seems like there should be tons of analog inputs left and the code should be small.

I am still waiting for the microchip chips, this week should be ok. My test setup will be a Freeduino and a daughterboard and a big bunch of wires, but I have enough components to build it on a small PCB (3" x 2") as a phase II.

I know how to use the photoresistor, anyway there is only one pin left!

LCD takes 8 (4 for data, contrast, brightness, select, enable)
MCP takes 5 (int, cs, si, so, sck)
Buttons takes 3
Voltage battery input takes 1
serial port debugging/logging takes 2

total, 19 pins used on 20

[Nevyn]

I have one vehicle with OBD-II ('99 Grand Prix), but it uses PWM signaling. I have a pair of MCZ33290EF chips from Freescale that I'd be willing to mail to someone if they can use them - I don't think I can with PWM.

If I do need one of these for PWM, I'm still willing to send the other one to a good home.

What is needed to make an OBDuino for PWM?

[Magister]

For PWM, there is some solution, fastest to do : an ELM327 (can do all protocol), or an ELM320 (cheaper, PWM only).

Other way is to use a couple of transistors/resistors and program the PWM protocol in the Arduino, maybe complicated...