SOC-LCD-Meter "LeafCAN" with 2x16 Display by lincomatic

Coincidentally, I tried to fit in a V*A kW number today, but didn't like the way it would affect the readout.
Basically, to fit it into 16 characters, I have to do, for instance,

393.5V273.5A-75.
298.0V256.0A-3.2

285.5 -75.5 -.45

It's either no spaces, or no units. Note the varying decimal precision in the KW number.
which is better? I don't like either style, partly because the decimal point needs to move around in the kw value while it's fluctuating wildly. Maybe I'll try it today, anyway, to see how it looks.

In the KWh remaining value, I also implemented the variable decimal places, but it changes slowly, so it's not so noticeable.

BTW, I have considered using Tony's GIDs * 75 factor instead, but I like 281 to display as 22.5 rather than 21.1.
In the end, it doesn't really matter which factor you use, once you get used to it, and it's rather easy to change.
Here is the relevant line from the code:

#define KW_FACTOR 80.0F // 80 is from phil, tonywilliams prefers 75

I decided to play around with adding the KW (VxA/1000) display to the second line today, it looks better
than I expected. The KW number matches up nicely to the sum of the 3 types of current draw displayed in
the onboard energy display.

More info and screen shot here: http://blog.lincomatic.com/?p=639

I have been EMAILING Lincomatic but he suggested it would be better here. I do not like the contrast of my white on blue display. It is hard to read in sunlight. I also suggested Adafruit's VFD display if he needs more space since it is a 2X20 Display.

Personally I am happy with the current display items. Slower updates would be nice.

I have ordered an Ebay China display that claims larger disits with a black on yellowish green. I hope it is an improvement.

I just flashed your ver 1.2 to my board. I left the top line alone but enabled the second line. The first effort was just fine but the smoothing really makes a difference. Good job!

The Voltage (and Amps) come in 0.5 resolution, and come Fast.

I add 20 together which gives me Voltage * 10 to display with one decimal point.

Same with Amps, to get Amps * 10.

The GID values are "infreuent", so I get % and truncate the hundredths rather than round to tenths, not wanting to show a too-large value.

I originally had code to average 25 samples, but for the purpose, I decided that was overkill, since the numbers change so rapidly.
Now, I just update the display with the current values, but limit the frequency of update to >= 250ms

Well I have spent a day with the new options. I find the display too busy. When I got home I flashed Ver 1.2 with the new options disabled.

Truth to be told I would be happy with only the top display but the second line is useful.

I do not see any need to display the used capacity with a decimal point. Whole digits are more than adequate.

I really like the smoothing.

For now I am finished with my CAN reader. It gives me just enough information without the screen being cluttered.

Yes, Tony Williams has with him a prototype 2x16 LCD SOC-Meter,
packaged in my black Box, on his BC2BC adventure.

No buttons or switches, it just shows the GIDs, %Gids, Fuel Bars,
Battery Pack Voltage and Curent (Amps) on one "screen".
There is no provision for switcing screens, but it still might
be entirely sufficient for some folks.

I wired this one to be Auto-ON (Off when the car is Off).

I have been asked: "Is that available?"

No, not yet, but I think ChrisH will be making/getting some
new prototype boards "soon".

It is not yet clear to me what will be included on the board.
These boards will require slightly modified firmware, I believe.

I will post here when something is available, even prototypes.

There will be very limited availability until we
get a "production" board to use.

one of them to OK

Yes, I do have another set of prototype boards coming very soon (1 - 2 weeks). Once validated, I will order a panel of 25 or so boards (another week).

Because Gary is making very good progress on a more powerful SOC that reads both busses, has data logging to SD, time stamping and other great features I decided to keep this SOC version as basic, simple and inexpensive as possible...

Supports 1 CAN bus at a time - can be reconfigured with jumpers or maybe a cable dongle.
16 x 2 LCD support with sleep mode and software definable contrast and brightness.
I/O pins available for buttons but they are optional.
Headers for FTDI USB, bluetooth or xbee etc.
Board has provision for onboard USB FTDI.
ODB cable is removable and connects with a RJ45 like Scangauge II.
Parts cost should be less than $100 (SOC board, LCD, ODB cable, enclosure)
Kits and Assembled versions TBD

Actually, the current version already has data logging capabilities, but right now, it's just a raw binary dump.

As far as multiple screens go, the hardware is set up to allow a few buttons to be added; I just haven't
found any need for that, currently.

I'm open to suggestions for added features, and since it's open source, anyone can feel free to hack it.
I would appreciate it if anyone adds useful features that they share the code, as well.

With this new board, how will the user adjust
the LCD contrast and brightness?

Gary the board has 4 I/O pins accessible to add whatever switch, button or rotary encoder etc. you would like if you wish to dynamically set the contrast and brightness values.

I plan to keep mine very simple with no buttons. Contrast is normally “set and forget”, most LCD have a physical trim pot. I will set the default contrast value in the firmware and probably never touch it again. For brightness, I plan to set a value for day, night and sleep and again will probably never touch it again.

I am hoping to have a device that is very small, simple to assemble, inexpensive and easy to operate.

We could just hook up the backlight to a PWM pin for brightness

We could just hook up the backlight to a PWM pin for brightness

Click to expand...

The v2 prototype board has both brightness and contrast on a PWM pin.

chris1howell said:

I am hoping to have a device that is very small, simple to assemble, inexpensive and easy to operate.

Click to expand...

Chris,
A good goal, I agree.
I was going to use my current Enclosure, but maybe you have
a better idea for packaging a "very" small unit?

Please let me know then I can buy a populated Version-2 board
so that I can make another prototype LCD "SOC" Meter.
Thanks, Gary

Lincomatic is doing experiments with 3d printing. If that does not go well I might try laser cut acrylic.

chris1howell said:

Lincomatic is doing experiments with 3d printing. If that does not go well I might try laser cut acrylic.

Click to expand...

Speaking of which ... I just finished assembling the carriage of my prototype of the new 3D printer I'm designing, and it's flying 4x the speed of my Printrbot, with zero vibration. Should be able to finish assembly and try some real printing with it tomorrow.

Chris,

How small do you think the Ver2 will be after assembly?