LCD Instrumentation for Cougar Controller

[Freyguy]

Mora,
Then I'd just wire in a 500 ohm potentiometer between sender wire and ground. See what resistance creates a full & empty condition. Will probably be in the 30~250ohm range. That will tell us what value to make R20 and if PWM needs to be inverted or not.

Sent you a pm with email

[mora]

Thanks a lot for your help. I think everything works now. SOC and KTE are spot on using peukert 1.00. Fuel gauge doesn't seem to be linear as it shows a bit over halfway when SOC is 50% and something like 7/8 full when 75% SOC. But it shows exactly full when 100% SOC and empty when 20% SOC. Doesn't matter me as LCD shows correct readings along all the other useful info.

[adamj12b]

I was wondering if anybody has a set of PCB's and looking to sell them?

I need one of these for a Motorcycle project im working on.

-Adam

[Freyguy]

Originally Posted by mora

Thanks a lot for your help. I think everything works now. SOC and KTE are spot on using peukert 1.00. Fuel gauge doesn't seem to be linear as it shows a bit over halfway when SOC is 50% and something like 7/8 full when 75% SOC. But it shows exactly full when 100% SOC and empty when 20% SOC. Doesn't matter me as LCD shows correct readings along all the other useful info.

Great Mora! Then I'll assume the fix for PWM duty below 20% SOC worked? I'll add that to version 1.4.
I suspect the orignal sender resistance wasn't linear over the full~empty range. Not sure if this is due to gas tank shape? or if original sender float arm moved in an arc? Wouldn't be surprised if this nonlinearity is the norm.
I suppose the 0~100% SOC values could be used as offsets to a 100 deep lookup table containing 8-bit PWM duty values. One would need to first set SOC to 20% and adjust VR2 while monitoring fuel gauge needle position and Q1 duty cycle. Measured duty would then be used to construct the table....very user specific but accurate.
So far running the display in automode works for me A few seconds after my foot is off the throttle, the SOC screen pops up. Most of my driving is stop & start so I get to see this often.

[mora]

Needle didn't bounce back to full when SOC went below 20%. I did reset SOC to 20% and drove 5km to work today, needle didn't get lower or higher. I'll do the same test again when I get back home. I'm not sure if this is a valid way to test it but I don't want to drain SOC under 20% too much. Maybe I could recharge when SOC reading is low but don't reset the meter.

"Automode" is cool feature, it works fine for me too.

[Freyguy]

Mora,
Setting to 20% is for calibration only. It disables timer1 which then prevents SOC updates. Not resetting SOC after pack recharge would work. I'm pretty sure the fix works as it was a very basic problem.

-Chris

[mora]

Yes, I thought it might be something like that. Now I didn't reset SOC and drove down to 16% SOC and needle remained in empty position. Tomorrow I'll continue draining SOC down to 0% and see what happens. I believe your fix works as it should be.

[mora]

Bad news, fuel gauge bounced back to full when SOC was nearing zero. It happened with lower SOC value than before the code fix. I will reprogram my chip once more and try if it still happens.

[pnikolaj]

Originally Posted by Freyguy

Pnikolaj,
Very sorry to hear about the board. If I had a spare I'd give it to you.
Schematics and wiring diagrams should never be used to determine physical orientation/location of connectors. Typically the silkcreen (overlay) on physical PCB would have a pin 1 indicator but I didn't have the room
An overlay drawing (like I included in the assembly instructions)or pin 1's called out on a picture of finished assembly are the next best thing.
I'll add the overlay to the manual right after wiring diagram. On wiring diagram I'll add note to reference overlay for pinout orientation. I'll make it part of package for version 1.4 release.

Thanks! It was my error. I made an assumption and have now learned (I hope) from it. I have not had any luck finding a replacement board and am thinking about ordering some. I tried uploading the files to BatchPCB so that others could order as well, but received this error "Unfortunately, your design "Cougar LCD" violates our design rules of 8 mil traces with 8 mil trace spacing." The error appears to be caused by "Traces are colored Purple if they violate the trace spacing requirements"

Any thoughts. Should I try elsewhere?

Thanks

[ianbartie]

If there are at least 6 takers for LCD Display PCBs, I am willing to get another batch made the same as before. My boards turned out 100%
Cost includes padded bag & postage worldwide by regular air mail.
AU$20 for 1 pcb
AU$36 for 2 pcbs.
Insurance and/or registered post can be done at extra cost.