touch screen based wheel chair using 89c52

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PARMAR DEEPAK

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• Mar 3, 2015

• #1

Dear,
how to read the coordinate of touch screen?That is 4 wire resitive touch screen.

 

Ian Rogers

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• Mar 3, 2015

• #2

Funny enough!!! Just done this.

https://www.electro-tech-online.com...-tutorials-code-and-info.123514/#post-1208917

 

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PARMAR DEEPAK

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• Mar 3, 2015

• #3

but how to interface 4 wire resistive touch screen with ADC0808?

 

Ian Rogers

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• Mar 3, 2015

• #4

You need two ADC channels one to read the X and Z values and one to read the Y values... You also need to switch in a positive to each plate... The ADC has eight channels but no way of swapping the positive supply.... Go to MikroElectronica and look at this book... The last example has a simple switching circuit..

 

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PARMAR DEEPAK

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• Mar 4, 2015

• #5

dear,
how will supply be given to touch screen.And how will ADC0808 give the digital output.

 

Ian Rogers

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• Mar 4, 2015

• #6

I drew up a circuit using a 4053... with a single ADC connected to a 8052 micro..

When A,B & C on the 4053 are low... You will be reading the X axis... When all three are high you will read the Y axis.

Unfortunately, you won't be able to read the z axis, as I cannot swap a Ground for a positive... It could be done if you supply a positive to the X axis whilst the 4053 is switched away from the ground...

 

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• 8052 touch.bmp

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PARMAR DEEPAK

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• Mar 5, 2015

• #7

Dear
tell me about this pot.I don't know how to connect it.

 

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Ian Rogers

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• Mar 5, 2015

• #8

I would imagine that A is the wiper.... All you need to do is check it with a multimeter.. Its a 50k trimmer so from B ~ C that will be the resistance... A will vary from one to the other!!

 

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PARMAR DEEPAK

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• Mar 6, 2015

• #9

dear how to make own touch screen panel

 

Ian Rogers

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• Mar 6, 2015

• #10

PARMAR DEEPAK said:

dear how to make own touch screen panel

Click to expand...

?????.. No idea... Its resistive clear plates... I can't imagine making one...

 

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PARMAR DEEPAK

New Member

• Mar 14, 2015

• #11

Dear how can i make my own ROM burner kit hardware for AT89s52.I wanna burn code using keil software.please tell me the ckt diagram for ROM burner kit

 

Tony Stewart

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• Mar 14, 2015

• #12

https://www.keil.com/dd/chip/3411.htm

 

Ian Rogers

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• Mar 14, 2015

• #13

Honestly... The easiest way is to use P89c52RD2 from phillips... You can use the internal bootloader..

The at89s52 can be programmed serially with a home brew circuit.. One of which looks like this. https://ece.jagansindia.in/2012/01/isp-programming-kit-for-at89s952-and-avr-seires/

I have found that its best to use the circuit that the burner software recommends.. So if you look on Keil's web site you should find such schematic..

 

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PARMAR DEEPAK

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• Mar 16, 2015

• #14

how microcontroler will know that the touch screen is touched.

 

Tony Stewart

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• Mar 16, 2015

• #15

**broken link removed**
https://www.keil.com/support/man/docs/mcbstm32c/mcbstm32c_to_lcd.htm

PMatrix area detection (PMAD) The PMAD works in combination with the PMSE. It reduces the CPU load by processing the information provided by the PMSE. It returns information on the touched areas. The PMAD can be served by the DMA controller

 

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PARMAR DEEPAK

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• Mar 16, 2015

• #16

but i am using 89s52 uc.how this will work with touch screen

 

Tony Stewart

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• Mar 17, 2015

• #17

choose parts ... read specs ... cap type http://www.atmel.com/products/TouchSolutions/touchscreens/unlimited_touch.aspx

 

Tony Stewart

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• Mar 17, 2015

• #18

I think you would be better off with capacitive grid on copper PCB for touch pad. Much simpler and can be clad with solder mask. Requires special MATRIX pattern and encoder.

For example.

https://repository.tudelft.nl/view/ir/uuid:e2234250-950d-4eb5-9f2e-b5b8e67af2e5/

**broken link removed**

note advantage of active guarding and variable sensitivity.

 

Last edited: Mar 17, 2015

Ian Rogers

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• Mar 17, 2015

• #19

If you use resistive touch screens, then reading the voltages as I have shown in post #6...
If you buy a specific Touch controller, you can connect to a serial port!

Something like this..

 

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PARMAR DEEPAK

New Member

• Mar 17, 2015

• #20

yes i m using resistive touch and using 4053 i am able to read the coordinate but how will 89s52 take decision. pls help me in coding