Please help me for my pressure mapping program

[PanR]

Thanks for the answer, but I still have question. If the actual messured value is constant, your code work perfect when I dont touch the sensor. In my case, even I don't touch the sensor. the value is keep changing. so this Code in the first loop it will be zero. But in the second loop, it will be not Zero in the Matrix. How can I fix this Problem?

[GerdW]

Hi PanR,

get a better sensor with less/no noise…

Or develop an algorithm to handle the signal noise.

[altenbach]

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wiebe@CARYA wrote:

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Isn't \n termination enabled by default? If so, 9600 read count would work if the data is indeed \n terminated.

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Yes, of course. It was just such an special number for no good reason. Most likely the terminal got recycled from elsewhere :D. A diagram constant in the low 3 digits would have been sufficient here.

[altenbach]

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@PanR wrote:

Thanks for the answer, but I still have question. If the actual messured value is constant, your code work perfect when I dont touch the sensor. In my case, even I don't touch the sensor. the value is keep changing. so this Code in the first loop it will be zero. But in the second loop, it will be not Zero in the Matrix. How can I fix this Problem?

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"Zero" does not really exist in nature, it is always about signal to noise. You should be able to tell insignificant readings form significant readings using some statistical analysis.

Also, negative values are perfectly legal, for example if you would tare with the finger on the sensor and then remove the finger, you'd expect negative values.

[wiebe@CARYA]

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@PanR wrote:

Thanks for the answer, but I still have question. If the actual messured value is constant, your code work perfect when I dont touch the sensor. In my case, even I don't touch the sensor. the value is keep changing. so this Code in the first loop it will be zero. But in the second loop, it will be not Zero in the Matrix. How can I fix this Problem?

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Of course if you don't want negative numbers, you could simply use a Min\Max with the array and a 0, and take the maximum.

Or replace values under a value, lets say 10, with 0.

All hacks. It's all about what you want.

[PanR]

I am programing a pressure mapping. When I press the sensor, it will has the value in the array. my problem now is in every loop the data will renew. so the old data will disappear. what I want to do now is setting a button that it can tracking my finger. every part of the sensor that I press will show in the array even when my finger leave, the value will still stay in the array.

picture 1 is how the sensor looks like.

picture 2 is how it looks like in labview when I press the sensor

because I am the beginner, please make it easier for me to understand. if I can get a example that will be best.

Thank you for every one

[GerdW]

Hi PanR,

please stick with your thread instead of creating new ones.

You already got several good advice in here!

[PanR]

I am programing a pressure mapping. When I press the sensor, it will has the value in the array. my problem now is in every loop the data will renew. so the old data will disappear. what I want to do now is setting a button that it can tracking my finger. every part of the sensor that I press will show in the array even when my finger leave, the value will still stay in the array.

picture 1 is how the sensor looks like.

picture 2 is how it looks like in labview when I press the sensor

because I am the beginner, please make it easier for me to understand. if I can get a example that will be best.

Thank you for every one

[PanR]

Here is the vi

[GerdW]

Hi Pan,

why do you ask me (in a PM) to read your messages carefully before joining your threads?

Hello, I am giving the new question. its totally different from the old one. Why u still put them together? have u ever read what I write in the new topic?

Yes, I read your messages!

In message #16 (end of December) you asked:

what I want to do now is setting a button that it can tracking my finger. every part of the sensor that I press will show in the array even when my finger leave, the value will still stay in the array.

6 weeks later in message #18 you asked:

what I want to do now is setting a button that it can tracking my finger. every part of the sensor that I press will show in the array even when my finger leave, the value will still stay in the array.

Why do you think this is a completely different problem now? Why do you complain about joining the threads?

You need to detect the actual finger press. When there is no finger on your pad anymore you need to clear your shiftregisters…