CapSense large intial sensor signal issue

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admic_2310931
Level 2
Level 2

Hello,

I have a CapSense slider project using the PSOC4000S that is giving me a bit of trouble at power up. I am getting a large sensor reading at startup that takes about 45 seconds to settle down. During this time the slider is unusable. The slider controls an LED light via PWM, it constantly flickers and is extremely annoying during this period. It is not something I could live with for a final product. Once settled it works well enough.

Can I eliminate this issue?

Some details:

- 45 seconds for the signal to settle, and the rawcount/baseline to follow each other.

- overlay 2mm wood

- Slider adheres to design guidelines

     - 220mm length, 15mm height

     - 12 segment diplexed

     - 8mm wide chevrons

     - 0.5mm gap between sensors

     - 0.5mm gap between sense traces and gnd

     - 1.75mm gap between sensors and gnd

     - End segments attached to ground

     - Central sensor ground point at PSOC

PCB stackup:

- L1 Top (Components, signals, sense traces, gnd)

- L2 (sense traces, gnd)

- L3 (gnd)

-L4 Bottom (sensor, gnd)

- SNR of approx 19

I will attach images of my PCB, main.c, CapSense settings and tuner graphs.

I appreciate any input, Thank you.

- Adam

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1 Solution

No dice xzng.

I "Think" I have made it work. I was using PSoC Creator 4.0/ CapSense P4 v3.1 to build this. I rebuilt the project in PSoC Creator 4.2/ CapSense P4 v5.2 and it seems to work correctly with my existing code.

However The V5.2 Sense tuner does not seem to work with the MiniProg3, I get " Bridge Status: Disconnected" My settings have not changed since the upgrade. I have confirmed the MiniProg3 is good by retrying the older Tuner.

I would like to view the Tuner, I will start a new thread with this issue. I will revisit this thread if I solve the Tuner Issue and see any problems with the results of that.

View solution in original post

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7 Replies
Anonymous
Not applicable

Dear Adam, as far as I can see, the boot-up takes far too Long time. I think the boot-up shall be finished in a second or less. So the Point is to find out where it hangs. I can not help you for the Software, but I will look carefully at the layout and come back soon with my Analysis for the layout.

I think a Time-out would not be so bad; but I dont know where to put it in the Software. I'm a hardware-guy. I think it's necessary to check, with which Task the Software hangs.

Best regards!

Jurgen.

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Hello Adam,

Could you also share your CapSense hardware and software/threshold parameters that was set by SmartSense?

Thanks,

Shanmathi

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Hi Shanmathi,

Here are the parameters, is this what you meant?

Thank  you,

Adam

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Hi Jurgen,

I will look into your suggestion, I have never done debugging like that so it may take me a while to figure it out.

Thanks,

Adam

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admic_2310931
Level 2
Level 2

I have put a bit more troubleshooting into this.

I think the issue is with SmartSense and maybe the Power-Up Tuning specifically. If I input similar values from the SmartSense Widget parameters into a manual tuning configuration and it works as I would have expected.

Is this startup behavior in the following image with SmartSense enabled normal? I don't know why it would start with a touch signal or why the baseline takes so long (45 seconds) to follow the raw count.

Tuner Graph at power up.png

In terms of debugging, I figured out how to step through the code in Creator with my Miniprog3. I however do not know what I should be doing or looking for... any pointers?

Thanks,

Adam.

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Vison_Zhang
Moderator
Moderator
Moderator
First comment on KBA 750 replies posted 250 sign-ins

Please try attached main.c.

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No dice xzng.

I "Think" I have made it work. I was using PSoC Creator 4.0/ CapSense P4 v3.1 to build this. I rebuilt the project in PSoC Creator 4.2/ CapSense P4 v5.2 and it seems to work correctly with my existing code.

However The V5.2 Sense tuner does not seem to work with the MiniProg3, I get " Bridge Status: Disconnected" My settings have not changed since the upgrade. I have confirmed the MiniProg3 is good by retrying the older Tuner.

I would like to view the Tuner, I will start a new thread with this issue. I will revisit this thread if I solve the Tuner Issue and see any problems with the results of that.

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