My Specs Engine: 318 Transmission: nv3500 Transfer Case: 231 Front Axle: d30 Rear Axle: ford 8.8, eaton e-locker, high clearance brackets Axle Gear Ratio: 3.73 Suspension: 4.5' claytons, currie ar, jcr 1ton steering, kor steering brace, triangulated rear shocks Tires: 35x12.5x15 baja claw radials Wheels: soft 8's Recovery: Hi Lift, come-along, and assorted straps, chains, hooks, and shackles. Armor: KOR prerunner bumper, KOR rad support, KOR LP-1 sliders Accessories: turbo city intake,1.7 HS rrs, hughes f1 intake, iron ram heads, e-fan, iceland offroad flares Future Mods: f250 hp44 & d60, d300, 408cid stroker. I probably wouldnt bother. You would need to know how the data is output (parity, start/stop bits, synchronous/asynchronous). I'd bet that you'd get ascii characters from the computer though. Thats what i'd have it send out if i designed the computer, but its hard to know for sure without testing and reading what is sent out.
You'd probably need to test and see what is output first and then you could have an easier time designing after that, much faster than just guessing until you get something that makes sense.
First Communcation Soldering Headers To create a solid electrical connection with any other components (such as an Arduino or an FTDI Basic), you need to solder headers to the board. For use with the FTDI Basic, it is easiest to solder male headers into the 6-pin header row at the edge of the board. Once you have this done, your board should look similar to this.
Example of a serial interface, transmitting one bit every clock pulse. If you've ever had to move a project from a basic Arduino Uno to a Mega, you know that.
OBD-II Board with Right-Angle Male Headers soldered onto it. Connecting to a Vehicle OBD Port You will need to connect the OBD-II board to the OBD port on your vehicle. Depending on the make and model of your car, the port location may vary. Consult your owner’s maunal if you cannot locate the port. Once you have located your OBD port, you will need to hook up the OBD-to-DB9 cable to the vehicle’s port.
The mating end of the cable tends to be a very tight fit and require a bit of force to get it sitting securely, so it’s usually easier to start hooking everything together between the car and the cable. Once you get the car and the cable connected, then connect the DB9 end of the cable to the OBD-II board. Connecting over a Serial Port Once you have your headers attached to your board, and you’ve connected to your vehicle using the OBD-DB9 cable, you can start communicating withe OBD-II board over through a serial port using an FTDI Basic breakout board.
The FTDI pinout matches with the 6 pin header on the OBD-II board, but only connects TX, RX and GND. Connect the FTDI board to the computer via a mini-USB cable, and open up a serial terminal on your computer. Configure the serial connection to 9600 bps, 8 data bits, 1 stop bit and no parity. Once you have your serial terminal set up, you will communicate with the OBD-II board by using AT commands. These commands always start with “AT”. The OBD-II board is case-insensitive, so don’t stress about only using capital letters. After sending “AT”, the next letters sent to the board will be the commands that should be executed by the board.
You can find a list of all of the available AT commands. To start communicating with the board, type “ATZ” into your terminal window and hit “enter”.
This will send the command to reset the board. You should see some LEDs flash on your board and then see the start-up prompt in the terminal window. If you receive back any garbled characters, double check that you have the correct serial port settings in your terminal. Once you have proper communcation with your board set up, try reading the OBD-II UART system voltage. Type “ATRV” into the terminal window and hit enter.
The board should then return the system voltage to you. This voltage reading should match your vehicle’s battery voltage.
To read additional OBD parapters for the vehicle, the OBD-II board must first be configured to the correct OBD protocol. There are several different, so it can be confusing attempting to find the correct one. However, like all things awesome, this OBD-II board automatically detects the protocol. To use this auto-detect feature, the vehicle’s ignition must be in the ‘On’ position.
The vehicle doesn’t necessarily need to be running however. Once the ignition is on, send the command “ATSP0” (that’s a trailing zero).
The board will then reply with “OK” once the proper protocol has been detected. Once you have the proper protocol detected on your board, you can start sending OBD commands to the board.
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