Component: Potentiometer (Analog Input)

Author	Matrix TSL
Version	1.0
Category	Analog Input

Component Source Code

Please click here to download the component source project: FC_Comp_Source_Potentiometer.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_Potentiometer.fcfx

Detailed description

No detailed description exists yet for this component

Examples

A simple example that shows how to use some common functions of the potentiometer in conjunction with an LCD.

Potentiometer Example

Using Fixed Voltage Reference

An example of a 0 to 1023 mV meter with a resolution of 1mv.

ADC using FVR

A PIC16F15324 is used since it has a Fixed Voltage Reference (FVR) register.

Bit0 and bit1 determine what the FVR is set at.

A line of C code is added to set the FVR to a gain of x1 = FVR of 1.024V:

FVRCON = 0b11000001;

With this setting, the Int value from ADC directly proportional voltage in mV.

E.g. a value of 732 = 732mV

Binary is used to make reading values a lot easier.

From the datasheet:

If you wanted to change the fixed voltage reference to 2.048V

Then change bit0 and bit1 of the C code to FVRCON = 0b11000010;

Filtering ADC Inputs

Simple example which uses a filtering technique to provide a digital low pass filter on the ADC readings. The output of the filter is 50% the ADC reading and 50% the previous reading.

LPFilter

In this example the output of the filter is 25% the ADC reading and 75% the previous reading.

LPFilter2

Analogue Inputs Window

The Analogue inputs window available from the View ribbon, allows you to see the values for all of the analogue inputs which are active in your program. They can also be manually altered by dragging the mouse along one of the sliders.

Data Recorder

An ADC based component will automatically add a trace to the data recorder window allowing you to get a view of the analogue data over time during simulation.

Macro reference

GetAverageByte

	GetAverageByte
Read the ADC as a byte
- BYTE	NumSamples
- BYTE	DelayUs
- BYTE	Return

GetAverageInt

	GetAverageInt
Read the ADC at full bit depth
- BYTE	NumSamples
- BYTE	DelayUs
- UINT	Return

GetByte

	GetByte
Read the ADC as a byte
- BYTE	Return

GetInt

	GetInt
Read the ADC at full bit depth
- UINT	Return

GetString

	GetString
Reads the ADC as a direct voltage
- STRING	Return

GetVoltage

	GetVoltage
Reads the ADC as a direct voltage
- FLOAT	Return

Property reference

	Properties
	Connections
	Channel
Analogue Input Channel - Which pin is the analogue input connected to?
	Settings
	VRef voltage
Used by the GetVoltage or GetString component macros to take an ADC reading and convert it into a Voltage. +VRef voltage x 10mV Default 500 = 5.0V
	VRef option
Defines what is used as the ADC maximum reference. ADC Range = GND to VRef Voltage VDD - Defines the microcontrollers power supply pin as the max reference, VREF+ Pin - Dedicated pin on the microcontroller to allow for a variable reference voltage.
	Conversion speed
Clock setting to select how fast the ADC peripheral will perform an ADC conversion. The FRC setting is based on a RC time base and so will vary with temperature and pressure. Other settings are generally based on divisions of the master clock.
	Acquisition cycles
Number of micro seconds to wait for the ADC input to charge before starting the analogue sample.
	Bit Depth
Maximum number of digital bits the ADC can sample. 8 bit = ADC range 0 - 255 10 bit = ADC range 0 - 1023 12 bit = ADC range 0 - 4095
	Retain Value
	Appearance
	Component Label
	LabelColour
	Show Connection Label
	Show Pin Value
	Colour Style
	Fill
	Frame Outline
	Frame Fill
	Pointer Outline
	Pointer Fill
	Text
	Tick Mark Outline
	Tick Mark Fill
	Cap Outline
	Cap Fill
	Main Image
	Cap Image
	Style
	Type
	Simulation
	Scope Traces
Selects if the scope traces are automatically generated or not