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Battery Indicator - Printable Version

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Battery Indicator - sirminder - 03-22-2014

Success!

I've placed everything together and looks good so far! Now to test the motor.

But first, a question regarding the battery indicator:

When I connect to a USB power source or a 12v dc source, should the indicator say 0%?

[img][Image: IMG_20140322_034532.jpg][/img]


RE: Battery Indicator - Airic Lenz - 03-22-2014

Hello and congratulations. The battery system is self calibrating and does not take USB voltages into account. After one full charge cycle the system knows your batteries min and max values which get saved on the Saturday card.

Cheers,
Airic


RE: Battery Indicator - sirminder - 03-23-2014

Thanks Airic for that info.

However, I am still puzzled by what is happening to my set up.

Everything runs fine when connected to a 12v dc adapter. But when I connect it to a fully charged 5000mAH, the battery indicator shows below 14% and the stepper motor just goes back and forth.

The voltage across the battery reads 12.48v and 12.15v on BED

Here's a short video that I hope helps to describe my issue.






RE: Battery Indicator - Airic Lenz - 03-23-2014

(03-23-2014, 10:00 AM)sirminder Wrote: Thanks Airic for that info.

However, I am still puzzled by what is happening to my set up.

Everything runs fine when connected to a 12v dc adapter. But when I connect it to a fully charged 5000mAH, the battery indicator shows below 14% and the stepper motor just goes back and forth.

The voltage across the battery reads 12.48v and 12.15v on BED

Here's a short video that I hope helps to describe my issue.




Did you adjust the motor current on the BEDs? To much current might be the problem.


RE: Battery Indicator - sirminder - 03-23-2014

(03-23-2014, 06:57 PM)Airic Lenz Wrote: Did you adjust the motor current on the BEDs? To much current might be the problem.

Thanks Airic, I did adjust the current on the BED from the default 3.01K down to 2.70K. At the point it reads 2.70K the motor stops doing its back-n-forth movement all together and does not move at all.

However, the battery lead cable I made was coiled up (as you can see in the video). So I uncoiled the cable and the motor began to move counter clockwise in intervals as it should. It was moving a bit jerky though. Then I began to adjust the current to fine tune it, but then then motor went back to its back-n-forth dance.

I also noticed the BED gets really hot. Is that something I should worry about?


RE: Battery Indicator - Airic Lenz - 03-24-2014

(03-23-2014, 09:37 PM)sirminder Wrote: ...
I also noticed the BED gets really hot. Is that something I should worry about?

you could add some heatsinks to the chips (with thermal adhesive) and / or add a fan to add some active cooling.

The driver chips work happily up too 100 degree Celsius but you are right - as lower the temperature the better. A general tip is also to reduce the motor current to the lowers needed value.

Cheers,
Airic


RE: Battery Indicator - sirminder - 03-25-2014

Ok, not exactly sure what it is I did, but the stepper is behaving better with the li-po battery.

Since I couldn't figure out what to do next, I simply went back to square one:
- Remove shields from Due
- Upload and run basic flashing led sketch on Arduino DUE
- Erase SD card, but I saved the .cnf file (there was only one file in the card)
- Return potentiometer back to position it was when I got it (3.01K ohms)
- Place both shields back on Arduino DUE
- Upload the miniEngine2.ino project
- Use with a fully charged battery
(I didn't know how to take the project back to its default stage, which is why I did the above. Even if I removed the sd card, the prior settings were still present. If there is a way to avoid doing all those things, please let me know)

Immediately after plugging the battery, I saw the battery indicator slowly climb up from 10% to about 60%. I know that it needs to go through a full cycle to learn the battery values, so I will let it do its thing.

The stepper stop doing its back-n-forth dance, but it was a bit jittery. I trimmed down the potentiometer a little and its a bit smoother now. I might turn it down some more, but I'm afraid it might go back to that back-n-forth thing again.

Oh yes one more thing, when I received my stepper (NEMA 23), the yellow and white wires had the ends twisted together. I know these are the center tap wires as per the data sheet, so they are not needed. But this time, I un-twisted them so I am not sure if that also had anything to do with it.

Thanks again for your help Airic!


RE: Battery Indicator - Airic Lenz - 03-25-2014

If there is no SD card present, the miniEngine will start up with default settings! If this was not the case, the Arduino was still powered somehow (USB?). To remove the settings permanently, just remove the settings file from the SD card. The next version will have 2 files - one for settings and one for the battery calibration values so that one can delete the settings without losing the battery calibration.

(03-25-2014, 02:13 PM)sirminder Wrote: ...
Oh yes one more thing, when I received my stepper (NEMA 23), the yellow and white wires had the ends twisted together. I know these are the center tap wires as per the data sheet, so they are not needed. But this time, I un-twisted them so I am not sure if that also had anything to do with it.

It sounds like the motor has 8 wires and in this case you need to connect the center tap wires - like in the 8 Lead Bipolar (Series) connection displayed here:

http://probotix.com/stepper_motors/unipolar_bipolar/

You need to make sure that the motor wires are converted to a bipolar setup the correct way.