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Old 01-29-2010, 11:56 PM   #2907 (permalink)
adamj12b
Master EcoModder
 
Join Date: Apr 2009
Location: Charlton MA, USA
Posts: 463

EVVette - '71 Chevy Corvette Coupe
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Quote:
Originally Posted by sawickm View Post
Hi Adam,

Good stuff !!! Sign me up for one of your PCB sets (controller - driver - expanded I/O). Just add your new proposed power board and you have a very nice system !!!
I will be sure to let you know when I am ready to start shipping kits!!


Quote:
Originally Posted by sawickm View Post
Don't tell me that’s your own conveyor driven reflow oven in your garage. And I suppose you have a paste stencil and pick-n-place machine too !!!
No, I dont have my own reflow oven. That is at my friends shop. He has 4 of those things!!

Quote:
Originally Posted by sawickm View Post
Why are you connecting your expanded I/O PCB into the ISP port? Is the ATMEGA8 I/O maxed out ??? Is there another compatible ATMEGA that has more I/O ?

Good job,

-Mark
We have decided to connect the expansion board to the controller through the ISP port for a few reasons.
- First, the original controller did not have signal conditioning resistors on the extra pins. This doesn't allow us to create a new board and allow the old ones to run the same firmware. By adding expansion through an external device allows all controllers to be able to run the same firmware. This method allows users to upgrade their controller with just plug and play.

- Second, the ISP port is actually a high speed serial data connection. After the firmware is loaded onto the micro, it is never used again. The 6 pin connector has the 3 data lines, reset, and 5V power. This means that the only connection needed between the 2 boards will be a 6 pin ribbon cable.

Quote:
Originally Posted by Grimm View Post
Wow, that surface mount version is awesome! Would it be a lot cheaper if a bunch of people order one?
YES!! If I can get a large order together before they go into production, prices will be lower. This will have to do with bulk ordering the expensive parts like micro controllers and opto-isolators.

I hope to keep some boards in stock after the initial run, but they will be slightly more because of smaller qty runs.

Quote:
Originally Posted by Grimm View Post
Also, any way you could give us a new current/planned feature list now that we're in the hardware adding phase again?
I will list what will be added with the expansion board.

- Bus Voltage Measurement
- Internal Pre-Charge Control
- Tach Input/Output w/ Scaling
- 1 Button Cruise Control w/ Brake Input
- Through Hole "Play Ground" for Custom Expansion


Quote:
Originally Posted by Grimm View Post
Another thought... is there some way to store the code on some sort of memory card for those of us who don't have the tools to program the at processors? Or maybe just store the log data on a usb/sd card so you don't have to have a computer with you in the car to record all the data like current, temp, and any software faults or errors? Kind of like what the PackTrakr does, only better. That would be awesome!
Yes!! You could use something like this : SparkFun Electronics - Logomatic v2 Serial SD Datalogger

It has inputs for a serial terminals. it takes a micro SD card which the adaptor is basically an SD card! I've never used one, But it says it can take 19200 baud serial data so it should work.

Quote:
Originally Posted by dcb View Post
integrating a vehicle speed sensor signal might have more than just monitoring energy per mile/speed uses.

some possibilities include
1. detecting wheel slip.
The only problem I have about integrating with the vehicle speed sensor is every make can be different.

Detecting wheel spin could still be done with just a tach sensor on the motor as the VSS will be inside the transmission which is close enough to the motor to work the same.

Quote:
Originally Posted by dcb View Post
2. rev matching for faster clutchless shifting, plug in the ratios and have one small pushbutton finger operated switch on the shifter to select rpm for the next gear (based on vehicle speed) and one to select the previous. controller can send a pulse or a brake to quickly find the next rpm.
Rev matching could be a cool feature. I will have to think of this more. The only problem comes back to interfacing to the VSS. The other thing that im not a huge fan of is connecting to the VSS is more intense of an install. You will have to locate the wire that is the VSS, and tie onto it and go back into the controller.

Quote:
Originally Posted by Grimm View Post
That sounds pretty sweet. Makes me think that this thing should get some code for cruise control as well after the speed sensor is installed.
The cruise control system I came up with would keep circuitry, wiring and installation very simple. The method I have came up with would require mounting 1 momentary push button for on/off and adjustment and a wire attached to the brake pedal sensor switch under the dash. The control switch would be be held down for 1 second to activate cruise control. 2 quick push's of the button would increase speed and 1 push would decrease speed. When the brake pedal is pressed, the signal will be sent and turn off the cruise control.

Quote:
Originally Posted by Grimm View Post
With the speed sensor you could have it act just like any other manual and give you a little light when you should change to a lower gear to get the absolute best range.
To do this you would probably need to have an efficiency variable in the controller that if you are over that, you the light would come on. Problem with that idea would be on the highway when you w/h per mile is high, the light would always be on...

Quote:
Originally Posted by Grimm View Post
Also, with fine RPM control and motor amps we could totally make it adapt to icy roads automatically. It wouldn't be too hard to make it determine when the wheels break loose and then have it give just enough power to get moving without making the wheels slip. Try doing that in an ICE!
I have thought about this before. It could be a very handy thing. It will take some more looking into and talking to Fran to see if this is possible. I have a feeling it might be harder then you think without removing and changing some parts of the firmware that are in place now.


So one other thing I think I forgot to mention is that this controller expansion will require that the main boards micro controller be upgraded from the atmega8 to the 168. The mega 8 doesn't have enough room to implement ANY thing else, including the serial communications to the new board.

Quote:
Originally Posted by Tweety View Post
Probably because the pins not used aren't pulled out to a connector, the ISP port is available in the boards already made... The next version should really bring any and all unused ports to a connector...
Yes, All of my bords will have expansion connectors and pull down resistors on all unused pins to allow for safe operation of firmware with features that are not implemented in hardware.


So what do you guys think?

-Adam
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You can download RTD Explorer for the Cougar controllers at www.EVVette.com
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