Analog PIN problem

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Anonymous
Not applicable

Hello,

   

So, my question is really simple, i need to connect an analog pin to an ouput analog pin. On the PSoC 4200 BLE CY8C4247LQ*-BL483 it work, but on the PSoC 4000 CY8C4014LQI-412, it doesn't work and i don't know why 😕

   

So do you have an idea?

   

My goal is to use an Amux later.

   

Thanks you 🙂

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rola_264706
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I don't have your part so I couldn't try the program. I made a program I added the Mux and the pins and it compiled without any issues.  This is a limited part with limited resources and may not work for you.  The CY8C4247LQ*-BL483 has a lot of resources and that is why you didn't get errors with it.  I am sending you the small program that I made with your information.

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Bob_Marlowe
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Just for clarification: Did you get any error when you built the project or doesn't one pin follow the other when you apply a voltage?

   

 

   

Bob

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Anonymous
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Hello

   

Thanks you for your help 🙂 But On both of your projects you are using CY8C4014LQI-421 (16-QFN), but i'm using the CY8C4014LQI-412 (24-QFN).

   

I have seen that there is not capsense on CY8C4014LQI-412, is it a problem to read Analog input?

   

My real application will be to create an I2C Mux. As you can see on my schematic, an I2C network is connected with my CY8C4014LQI-412 on the chip form PTOP.

   

I will more explain my application to be clear. My goal will be to create an I2C network using Amux.

   

As you can see on my captures, SCL signal is common on all port, but SDA is not. SDA_A, SDA_B, SDA_C will be used to create a first ONE-WIRE communication with the next bloc. After this first com (it's like an init), i will connect SDA_T with SDA_A (for exemple if there is bloc on this port) to continue the I2C network from SDA_T. (BTW, here SDA_T is still not configured in I2C to be more simple)

   

I hope i'm a bit more clear 😄

   

   

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rola_264706
Level 8
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You didn't tell us what your failure was with your design. Also this is a digital design not analog correct?

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Anonymous
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Oh yes,

   

Well i'm still trying to connect with the Amux SDA_INPUT and SDA_A with analog pin but it doesn't work. I tried your design but when i change the value of SDA_INPUT, it doesn't change the SDA_A.

   

I don't know if it's because i'm using the wrong chip, because with my CY8C4247LQI-BL483 it work 
easily.

   

I don't know why it doesn't work with the CY8C4014LQI-412.

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rola_264706
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But you are using I2C signals not Analog. So you need a digital mux not an Analog mux.

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Anonymous
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Yes it what i thought but a guy from cypress gave us this attached schematic to be a solution for our application. 

   

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rola_264706
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If you are using I2C you don't need to mux the signals as each device has it's own address so it will not answer if the data is not for it.  Please post your programs for both devices so we can check the design.

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rola_264706
Level 8
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I think that you are limited by this chip and its resources.  I would use the CY8C4247LQ*-BL483 as it has a Multiplexer component and other parts that will make your design easier. I would stay away from the Analog Multiplexer it may work but it is not a digital device and may affect your slew rates on your digital signals .

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Bob_Marlowe
Level 10
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My project did use a  CY8C4014LQI-412 and it compiled without any error.

   

Can you please post your complete project, so that we all can have a look at all of your settings. To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.

   

 

   

Bob

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Anonymous
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Here is my project

   

I begin to think that it's not possible to use Amux because there any ADC. I saw another part with the same footprint and pinout, with a capsense and ADC : CY8C4014LQI-422. Maybe it could be better no?

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