LCD Instrumentation for Cougar Controller

[E Vdubya]

For those that need a display I ordered mine from Crystalfontz America. The part number is CFAH1602LTGHJT. This is a blue display. They had other colors when I was looking. It was a little pricey but the same physical size as the original on the BOM.

I got a real cheap one ($7.49) from 411 Technology. It is half the size as what was called out. It will work but mounting it would call for some creativity. I'm sure I'll find a use for it someday.

So Chris I may come down Satuday. It's a bit of a drive but I would love to see what's going on.

John

[mrbigh]

Originally Posted by E Vdubya

For those that need a display I ordered mine from Crystalfontz America. The part number is CFAH1602LTGHJT. This is a blue display. They had other colors when I was looking. It was a little pricey but the same physical size as the original on the BOM.

I got a real cheap one ($7.49) from 411 Technology. It is half the size as what was called out. It will work but mounting it would call for some creativity. I'm sure I'll find a use for it someday.

So Chris I may come down Satuday. It's a bit of a drive but I would love to see what's going on.

John

I got the same one from Crystalfontz America. Yes, it's pricey but.... worth it? Maybe
Regards

[Freyguy]

Originally Posted by E Vdubya

I got a real cheap one ($7.49) from 411 Technology. It is half the size as what was called out. It will work but mounting it would call for some creativity. I'm sure I'll find a use for it someday.

So Chris I may come down Satuday. It's a bit of a drive but I would love to see what's going on.

John

The one I'm referring to is this for $13.28. Shipping adds another $5.99
16x2 HD44780 Large Character LCD

It's the larger size characters and is identical to the one from eio.
I wouldn't be suprised if it's from the same manufacturer (Orient Display)

John, don't sweat it if you can't make it. I'll post the pics here (or new thread). I might even bring the flip video to capture Adam's charger demo.

-Chris

[1-ev.com]

Originally Posted by Freyguy

The one I'm referring to is this for $13.28. Shipping adds another $5.99
16x2 HD44780 Large Character LCD

It's the larger size characters and is identical to the one from eio.
I wouldn't be suprised if it's from the same manufacturer (Orient Display)

-Chris

That the one I've ordered instead of Orient Display, I will let you know who makes it :-)
-Y

[harlequin2]

I've just connected the thermistor for Tmot to my board and it reads just on 3 deg high. That is, showing 27 deg C when my fairly accurate thermometer says 23.7. Is this about the best accuracy one can expect? Or is there something that needs trimming somewhere?
Further, I have connected the one for Tbat also and it reads the same 27 deg - as one would hope!

Now here's an interesting thing! The increase in temp is explained by the fact that my desk light is only a metre or so away and the IR it puts out is enough to warm the thermistors by a couple of degrees! If I shade them from the light, they drop back to about the same as my thermometer. Quite amazing.
Anyway, I guess they are more than accurate enough for the purpose.

[Freyguy]

Originally Posted by harlequin2

I've just connected the thermistor for Tmot to my board and it reads just on 3 deg high. That is, showing 27 deg C when my fairly accurate thermometer says 23.7. Is this about the best accuracy one can expect? Or is there something that needs trimming somewhere?
Further, I have connected the one for Tbat also and it reads the same 27 deg - as one would hope!

Now here's an interesting thing! The increase in temp is explained by the fact that my desk light is only a metre or so away and the IR it puts out is enough to warm the thermistors by a couple of degrees! If I shade them from the light, they drop back to about the same as my thermometer. Quite amazing.
Anyway, I guess they are more than accurate enough for the purpose.

Hey there harlequin2! Yeah, isn't that interesting with the IR? Imagine if the thermistors were black instead of blue
This board was not designed with test equipment accuracy in mind. Just accurate enough to know what's going on with various aspects of the car. There are trims for traction and accessory battery voltages since these need a bit more accuracy.
The thermistors are cheap 2% parts. The resistor divider on the board uses 1% parts. Raw temp has 8-bit accuracy (0.4%) and the conversion from F to Celcius uses 9/16 vs 5/8 (1/2 deg C error). And behind it all is the ADC reference which I chose to use the +5V supply versus a dedicated voltage reference (would have lost an ADC port in the process). I tried to keep this tight though which is why I spec'ed in a 2% regulator vs 5%. So if you stack up all the errors worst case is around +/-6% on temp.

[Nevyn]

Originally Posted by Freyguy

Yep! Saturday 10:00-3:00 at Macungie Memorial Park. Suppose to be sunny and in the 70's. I'll be there but without my conversion
It passed the enhanced PA inspection 2-1/2 weeks ago, but had to submit paperwork to DOT and am still waiting for my modified vehicle registration and license plate. My luck I'll get them next week.

Adam's going to be there with his display of the 1000amp Open source controller and 6kW charger. Should be a great show and I plan to take lots of pics.

-Chris

I'll be there too!

[Freyguy]

Cool Nevyn!
I'll see you there. Once you find Adam's display you can ask him where I am. He'll point me out.


-Chris

[harlequin2]

That should be 5/9 not 5/8. Typo? So that's 1.25% conversion error. Now, if you had used proper units in the first place, the conversion error would be from Celsius to Fahrenheit (:-)

[Dwffy]

Please could you put me down for 1 as well.