Engine Management

I was going to run the code when I got home from my real job. Then, I started setting up my bench, connecting up all the parts, and plugging in the power, sat back in my chair, and blinked. Three hours later, my wife told me I would probably be more comfortable sleeping in bed.  So, I didn't get a chance to compile all this stuff, and I don't have my bench set up here at work. I can provide a few extras in order to move things along, like circuits. People here seem to like circuits.

The Nano has a bunch of pins to connect the 328 to the outside world.

I am not an Electrical Engineer, but I have had a lot of experience dealing with circuits and circuit design (mostly at the logic level), and things I throw together on a breadboard tend to work, so please understand any circuits I provide, would do well to have a serious design overview performed.

With that in mind... the Nano has two sets of connecters on either side of the board. One side is primarily the A/Ds, and the other side is listed as D0 - D13. For the project, the D0 and D1 will remain reserved for serial communication (works through the USB), D2 and D3 will be the interrupt inputs for crank and cam signals (this will be circuit 1). D4 through D11 will operate the output latches (this will be circuit 2). The analog lines are tricky, and open to all sorts of opinion, so I will offer a simple solution, and let people with more knowledge make comment (circuit 3).

Circuit 1: The circle is for 12v Vbatt (should have a resistor to regulate. The arrow is the crank or cam signal (same circuit for both). The box is the line that goes to either D2 or D3 depending. The IC is just a simple comparator (like an LM2903).

Circuit 2: The box on the left is a 74ls138, the input lines go from top to bottom D7 (enable), D4 (A0), D5 (A1), and D6 (A2). The outputs route through a 74ls04 hex inverter. The inverter connects to the enable 1&2 and enable 3&4 of the 75ls75 (one of 6 shown). The other inputs of the 74ls75 are connected to D8 (1D), D9 (2D), D10 (3D), and D11 (4D). The D8-D11 connect the same to all 6 of the 74ls75 ICs. If you would like, you can add another 04 and two more 75s and have 32 output lines, but 24 is satisfactory for this application.

Circuit 3: Analog lines are all similar and only need to provide a simple divider. The sensors that are attached are the governing elements here. The simple divider is shown. Where the circle represents some sort of variable resistance sensor, and the line on the left attaches to the A/D input. Though looking at this, it probably needs a pull up resistor someplace. Again, just a play circuit for now.

I was going to run the code when I got home from my real job. Then, I started setting up my bench, connecting up all the parts, and plugging in the power, sat back in my chair, and blinked. Three hours later, my wife told me I would probably be more comfortable sleeping in bed.  So, I didn't get a chance to compile all this stuff, and I don't have my bench set up here at work. I can provide a few extras in order to move things along, like circuits. People here seem to like circuits.

The Nano has a bunch of pins to connect the 328 to the outside world.

I am not an Electrical Engineer, but I have had a lot of experience dealing with circuits and circuit design (mostly at the logic level), and things I throw together on a breadboard tend to work, so please understand any circuits I provide, would do well to have a serious design overview performed.

With that in mind... the Nano has two sets of connecters on either side of the board. One side is primarily the A/Ds, and the other side is listed as D0 - D13. For the project, the D0 and D1 will remain reserved for serial communication (works through the USB), D2 and D3 will be the interrupt inputs for crank and cam signals (this will be circuit 1). D4 through D11 will operate the output latches (this will be circuit 2). The analog lines are tricky, and open to all sorts of opinion, so I will offer a simple solution, and let people with more knowledge make comment (circuit 3).

Circuit 1: The circle is for 12v Vbatt (should have a resistor to regulate. The arrow is the crank or cam signal (same circuit for both). The box is the line that goes to either D2 or D3 depending. The IC is just a simple comparator (like an LM2903).

Circuit 2: The box on the left is a 74ls138, the input lines go from top to bottom D7 (enable), D4 (A0), D5 (A1), and D6 (A2). The outputs route through a 74ls04 hex inverter. The inverter connects to the enable 1&2 and enable 3&4 of the 75ls75 (one of 6 shown). The other inputs of the 74ls75 are connected to D8 (1D), D9 (2D), D10 (3D), and D11 (4D). The D8-D11 connect the same to all 6 of the 74ls75 ICs. If you would like, you can add another 04 and two more 75s and have 32 output lines, but 24 is satisfactory for this application.

Circuit 3: Analog lines are all similar and only need to provide a simple divider. The sensors that are attached are the governing elements here. The simple divider is shown. Where the circle represents some sort of variable resistance sensor, and the line on the left attaches to the A/D input. Though looking at this, it probably needs a pull up resistor someplace. Again, just a play circuit for now.

Jack.

Yes, please. Pay attention to what your wife says. It will make the results better for you, everyone. :-)

Still trying to catch up with all the details but I'm enjoying reading thru it all.  I  want to encourage your postings.  I'm not in the automotive industry but chemical industry. It's all kind of the same and all a bit different.

I thought I would clean things up a bit...

Attachments:

E14_ECM.pdf