motorized_fader/tests/ADC/test_ADC.cpp

/*
 * Author: Jake G 
 * Date: 2025
 * filename: test_ADC.c
 * description: module_purpose
 */

#include "CppUTest/CommandLineTestRunner.h"
#include "CppUTestExt/MockSupport.h"
#include <cstdint>

//This define allows us to dircetly include the device header without error.
#define _AVR_IO_H_


extern "C" 
{
#include "sfr_defs.h"
#include <iotn13a.h> //ATtiny13A header file.
#include "ADC.h"
}

TEST_GROUP(test_ADC)
{
    void setup()
    {

    }
    void teardown()
    {
        mock().checkExpectations();
        mock().clear();
    }
};

TEST(test_ADC, FirstTest)
{
   CHECK(true);
}

TEST(test_ADC, ADC_SetupSetsRegisters)
{
    /*
     * ADC Channel Selection(MUX1, MUX0):
     * 00 == ADC0/PB5
     * 01 == ADC1/PB2
     * 10 == ADC2/PB4
     * 11 == ADC3/PB3
     */

    /*Set the ADC Channel 0 (default) using ADMUX reg*/
    /*Set the voltage reference to VCC.*/
    /*Set ADC Left adjust result setting to off.*/
    mock().expectOneCall("RegEdit_ClearRegister")
        .withPointerParameter("reg", (void *) &ADMUX);

    /*ADC0 Status and Control Register A*/

    /*Set the Prescaler (F_CPU/8) for samping frequency.*/
    mock().expectOneCall("RegEdit_SetNum")
        .withPointerParameter("reg", (void *) &ADCSRA)
        .withUnsignedIntParameter("num", 3);
    
    
    /*ADC0 Status and Control Register B*/

    /*Setup the auto-trigger source.*/
    /*Using timer compare/match B for now.*/
    mock().expectOneCall("RegEdit_AND_Num")
        .withPointerParameter("reg", (void *) &ADCSRB)
        .withUnsignedIntParameter("num", 5);

    ADC_Setup();     
}

TEST(test_ADC, ADC_InitRejectsInvalidChannels)
{
    for(uint8_t i = 4; i < 255; i++){
        ADC_Init(i);
    }
}


TEST(test_ADC, ADC_InitPortbWorksWithValidChannels)
{
    uint8_t pin_num;

    for(uint8_t adc_channel = 0; adc_channel <= 3; adc_channel++)
    {
        pin_num = ADC_GetChannelPinNum(adc_channel);

        //Check it disables the pin's digital circuitry

        //Check it sets the pin for input
        mock().expectOneCall("RegEdit_ClearBit")
            .withPointerParameter("reg", (void *) &DDRB)
            .withUnsignedIntParameter("bit_num", pin_num);


        //Check that the pull-up resistor is disabled.
        mock().expectOneCall("RegEdit_ClearBit")
            .withPointerParameter("reg", (void *) &PORTB)
            .withUnsignedIntParameter("bit_num", pin_num);


        //Check that the ADC pin is selected in ADMUX

        //Clears the last two bits first.
        mock().expectOneCall("RegEdit_AND_Num")
            .withPointerParameter("reg", (void *) &ADMUX)
            .withUnsignedIntParameter("num", 0xFC);

        //Selects the ADC pin/channel
        mock().expectOneCall("RegEdit_OR_Num")
            .withPointerParameter("reg", (void *) &ADMUX)
            .withUnsignedIntParameter("num", adc_channel);

        ADC_Init(adc_channel);
    }
}


TEST(test_ADC, ADC_EnablePasses)
{

    mock().expectOneCall("RegEdit_SetBit")
        .withPointerParameter("reg", (void *) &ADCSRA)
       .withUnsignedIntParameter("bit_num", ADEN); 

    ADC_Enable();
}


TEST(test_ADC, ADC_DisablePasses)
{
    mock().expectOneCall("RegEdit_ClearBit")
        .withPointerParameter("reg", (void *) &ADCSRA)
        .withUnsignedIntParameter("bit_num", ADEN);

    ADC_Disable();
}

TEST(test_ADC, ADC_ReadValueImplimentationTimesOut)
{
    //Expect the start conversion bit to be set.
    mock().expectOneCall("RegEdit_SetBit")
        .withPointerParameter("reg", (void *) &ADCSRA)
        .withUnsignedIntParameter("bit_num", ADSC);

    //Check that it can time out.
   
    //Expect it to read the start bit 
    mock().expectNCalls(ADC_WAIT_TIMEOUT, "RegEdit_IsBitSet")
        .withPointerParameter("reg", (void *) &ADCSRA)
        .withUnsignedIntParameter("bit_num", ADSC);

    //Check that it return the "error" value

    uint16_t value = ADC_ReadValue();
    CHECK_EQUAL_TEXT(UINT16_MAX, value, "ERROR: Should return UINT16_MAX!");
}


static uint16_t ADC_ReadValueFake()
{
    return 512;
}

TEST_GROUP(test_ADCReadPtrSwap)
{
    void setup()
    {
        UT_PTR_SET(ADC_ReadValue, ADC_ReadValueFake);
    }

    void teardown()
    {

    }
};

TEST(test_ADCReadPtrSwap, FunctionPointerSwapWorks)
{
    uint16_t value = ADC_ReadValue();
    
    LONGS_EQUAL(512, value);
}