I'm working on building my own EVSE (Electric Vehicle Supply Equipment) that is SAE J1772-2010 compliant. Unfortunately generating the control pilot signal is a bit more complicated than blinking an LED or reading an RFID tag, so I need some help.
The basic equipment I'm already using includes a 12 volt DC power supply, powering a Parallax Super Carrier Board with a BASIC 2 Stamp. I'm using the microcontroller to read an RFID tag and display information on an LCD display.
The element I'm missing is some way to generate a 1 KHz, +/- 12V PWM square wave signal, whose duty cycle is controlled by the BASIC 2 Stamp. For example, a 8% duty cycle will let the vehicle know it can draw 6 amps, 20% draws 12 amps. The recommend frequency tolerance and duty cycle tolerance is ±2%. Attached is the technical document on J1772 if it helps describe things a bit clearer!
I'll be documenting my project here and on the MyNissanLeaf.com forum so that others can take advantage of what I learned by going through the process, so any help is greatly appreciated!
| SAE J1772-2010 SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler.pdf |
