Creator error: Signal "AH_0deg_w" is expected to connect to only one GPIO analog pin but instead it connects to "\SnH_AH_0deg:SC\".

[Anonymous]

I'm not sure about the meaning of the error message: 

   

Signal "AH_0deg_w" is expected to connect to only one GPIO analog pin but instead it connects to "\SnH_AH_0deg:SC\". Please fix the connection.... in my design. Does it mean the ADC SAR Seq's muxer can be connected only to analog GPIO pins? 

   

I didn't read about it in the datasheet. In this case, why the restriction? 

   

Ans:

   

In PSoC 5LP, the SAR ADC uses analog hardware mux internally to switch between channels. Analog hardware mux is controlled by the switches near GPIO, which are controlled by DSI lines.

   

Hence, the input to the analog hardware mux can be only from an analog GPIO and ADC SAR Seq's muxer can be connected only to analog GPIO pins.

   

[Anonymous]

3 years later ...

   

I was trying to modify the Psoc5 thermistor example (CE210514) by exchanging the AMux+ADC_DelSig combination by using the ADC SAR Sequencer. The example uses internal analog connections (VDAC+OPAMP blocks are connected to an AMux block). Furtherly are some other AMux pins connected to other AMux pins, as well as to the GPIOs (for resistors). Any of this connections throw error during build, for instance Net On Amux "is expected to connect to only one GPIO analog pin but instead it connects to "\Opamp:ABuf\".

   

It seems that the AMux and the "AMux within ADC SAR Seq" are not equivalent. 

   

Am I missing something here?

   

Matija

[Bob_Marlowe]

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

[Anonymous]

Hi Bob, 

   

Thank you very much for your prompt reply!

   

Attached please find the project.

   

Regards,

   

Matija

[Bob_Marlowe]

Remove the internal connection between VOpamp and Vhi. This connection is made extern to the chip.

       

Bob

[Anonymous]

Hi Bob, 

   

Sure, I made an additional external connection to make it work (and had to assign additional pin for additional external wiring). But this kind of decreases the charm of the Psoc, where the analog connections are possible internally (and pins can be saved). I left the internal connection intentionally so that the error could be reproduced.

   

It does work with AMux+ADC SAR though:

   

Regards,

   

Matija

[Bob_Marlowe]

The external connection makes sense: There could be voltage losses to the sensor due to cabling which can be eliminated with the given circuit.

   

The input to the multiplexer must be a GPIO pin.

       

Bob