#P2231 returns V2 when nothing is grabbed

[jim]

uArm Serial No.: E06234CC4CE2

Firmware Version: 4.9.0

Operation System: Win 10

uArm Controlling Method: Arduino Serial Monitor

Thanks for the great product!

After enabling the pump with “#M2231 V1”, the command “#P2231” always returns “ok V2”, even when nothing is grabbed. From my understanding, “ok V1” should be returned when the pump is running but nothing is grabbed, and “ok V2” should be returned when something is grabbed.

Is there something I could do to fix this?

Regards,
Jim

[Minna]

Dear Jim,

The grab detection is based on current, but as we know different objects have different surfaces, and it will also affect the air pressure which means the current is different. It is really hard to detect the grabbing or not by current, so we always don’t recommend you to try this feature.

If there are still some doubts, please take a screenshot of SN on the bottom of uArm and provide it to minna.zhong@ufactory.cc.

Best regards,
Minna

[jim]

Thank you for the reply, it makes sense that a grabbed state could be difficult to calculate for all cases.

Is it possible to get the raw current value from the arm? I’m wondering if it would be possible to calculate the grabbed state for my particular application, based on the observed current values.

Regards,
Jim

[Minna]

Hi Jim,

Please try ‘P2241 N9’, it returns the converted voltage value from 0 to 4096, which corresponds to the voltage from 0 to 3.3V.
As the voltage that grabs different objects may be different, the voltage standard for judging if something is grabbed needs to be tested yourself.

Best regards,
Minna

[jim]

This worked great, thank you!

I found it was helpful to average a few return values, and that there was a bit of time needed after grabbing before the return value changed to something that would indicate a grab.

In my particular situation, values < 33 indicated a grab.

Thanks again!
Jim

[Minna]

Hi Jim，

That’s great! Any problems feel free to let us know.

Best regards,
Minna