We are hard at work (well, sort-of) designing an interface board specifically for those Electric car hackers out there. We felt that now was the time to reach out to the hardware hacker crowd to gather thoughts on the features of our board in order to make a great product. We've got some of the major aspects nailed down, but we could use another round of brainstorming.
A little background: It seems that there just aren't many good options for people who are building/converting their electric car when it comes to instrumentation. Sure, there are a few simple 2 line LCD displays that show battery voltages and current draw or whatever - but nothing is very customizable or good-looking. In addition, there are just so many different cars people are converting and manufacturers don't always use the same standards.
So, lets say for example that we want to get the original tachometer needle moving again after removing the engine from the car, calculate the vehicle speed knowing motor RPM and gear ratios, displaying on a nice big graphical LCD, and logging everything to an SD card. Or maybe, measure the current flow through a wire while keeping track of overall distance traveled using a GPS module and then calculating efficiency of the car in kW•h/mile and displaying that on a cool analog gauge.
How can we design a board that can do all of this and still be easy to set up and program - thats right, you guessed it: Arduino.
So here's the plan: the EVduino, Electricarduino, or...we will think of a better name than these I am sure.
- Based on Arduino MEGA board - plenty of I/Os, serial ports, etc.
- built-in OBD2/CAN interface to communicate with original car computer or new EV parts.
- designed to run off of raw 12 volts from car's electrical system.
- screw terminals for more secure connections,
- optical isolation on some/or all I/O lines.
- maybe some relays pre-installed.
- maybe a USB host port to talk to our other EV sensors via our "OpenAPI EV Management packet structure" as seen here: http://www.rechargecar.com/openness
- maybe a fancy enclosure to create a more durable and less interference-susceptible system.
I am sure that there are other features people might like to see (or not want to see). Any thoughts? We are all-ears.