From a00e17667563fd2fd6877ff5eb02348361797ec3 Mon Sep 17 00:00:00 2001
From: jake <jakegoodwin@tutanota.com>
Date: Sun, 23 Feb 2025 09:50:09 -0800
Subject: [PATCH] Added testing for the pin number and resolving it from a adc
 channel input.

---
 src/ADC/ADC.c          | 35 +++++++++++++-----------
 src/ADC/ADC.h          |  6 +++++
 tests/ADC/test_ADC.cpp | 61 +++++++++++++++++++-----------------------
 3 files changed, 53 insertions(+), 49 deletions(-)

diff --git a/src/ADC/ADC.c b/src/ADC/ADC.c
index 21c9532..e0f558c 100644
--- a/src/ADC/ADC.c
+++ b/src/ADC/ADC.c
@@ -15,7 +15,14 @@
 
 #define MAX_CHANNEL_NUM 3
 
-static uint8_t GetChannelPinNum(uint8_t adc_chan) {
+static bool IsInvalidChannel(uint8_t adc_chan) {
+  if (adc_chan > MAX_CHANNEL_NUM) {
+    return true;
+  }
+  return false;
+}
+
+uint8_t ADC_GetChannelPinNum(uint8_t adc_chan) {
   switch (adc_chan) {
   case 0:
     return PB5;
@@ -30,13 +37,6 @@ static uint8_t GetChannelPinNum(uint8_t adc_chan) {
   }
 }
 
-static bool IsInvalidChannel(uint8_t adc_chan) {
-  if (adc_chan > MAX_CHANNEL_NUM) {
-    return true;
-  }
-  return false;
-}
-
 void ADC_Setup(void) {
   // Clear the register, set VCC as ref, ADC0 as channel and
   // leave result right adjusted.
@@ -57,17 +57,22 @@ void ADC_Init(uint8_t adc_chan) {
     return;
   }
 
+  // get the associated pin number.
+  uint8_t pin_num = ADC_GetChannelPinNum(adc_chan);
+
   // set the direction to input
-  RegEdit_ClearBit((void *)&DDRB, adc_chan);
+  RegEdit_ClearBit((void *)&DDRB, pin_num);
 
   // Disable the pull-up resistor
-  RegEdit_ClearBit((void *)&PORTB, adc_chan);
+  RegEdit_ClearBit((void *)&PORTB, pin_num);
 
-  // Disable input buffer
-  // We do some kinda nasty address addition but it saves
-  // memory and means we don't need a switch statment.
-  // RegEdit_SetBit((void *)(&PORTA.PIN0CTRL) + adc_chan,
-  //               PORT_ISC_INPUT_DISABLE_gc);
+  // Set the adc mux reg for our channel.
+
+  // Clear the existing mux bits.
+  RegEdit_AND_Num((void *)&ADMUX, 0xFC);
+
+  // Set the correct bits
+  RegEdit_OR_Num((void *)&ADMUX, adc_chan);
 }
 
 void ADC_Enable(void) {
diff --git a/src/ADC/ADC.h b/src/ADC/ADC.h
index c369fa6..33c6026 100644
--- a/src/ADC/ADC.h
+++ b/src/ADC/ADC.h
@@ -27,6 +27,12 @@
  */
 void ADC_Init(uint8_t adc_chan);
 
+/**
+ * @brief Returns the pin number for the adc channel or 255 on an error.
+ * @param The ADC channel.
+ */
+uint8_t ADC_GetChannelPinNum(uint8_t adc_chan);
+
 /**
  * @brief Enables the ADC
  */
diff --git a/tests/ADC/test_ADC.cpp b/tests/ADC/test_ADC.cpp
index 292d30c..69ddd19 100644
--- a/tests/ADC/test_ADC.cpp
+++ b/tests/ADC/test_ADC.cpp
@@ -80,50 +80,43 @@ TEST(test_ADC, ADC_InitRejectsInvalidChannels)
     }
 }
 
-TEST(test_ADC, ADC_InitPortbADC3UsesCorrectRegisters)
+
+TEST(test_ADC, ADC_InitPortbWorksWithValidChannels)
 {
-    //PB3/ADC3
-    //uint8_t adc_channel = 3;
-    uint8_t pin_num = 3;
+    uint8_t pin_num;
 
-    //Check it disables the pin's digital circuitry
+    for(uint8_t adc_channel = 0; adc_channel <= 3; adc_channel++)
+    {
+        pin_num = ADC_GetChannelPinNum(adc_channel);
 
-    //Check it sets the pin for input
-    mock().expectOneCall("RegEdit_ClearBit")
-        .withPointerParameter("reg", (void *) &DDRB)
-        .withUnsignedIntParameter("bit_num", pin_num);
+        //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 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
-    
+        //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);
 
-    /*
-    //Check for setting the direction to input.
-    mock().expectOneCall("RegEdit_ClearBit")
-        .withPointerParameter("reg", (void *) &PORTA.DIR)
-        .withUnsignedIntParameter("bit_num", 7);
- 
-    //Check that the pullup is off 
-    mock().expectOneCall("RegEdit_ClearBit")
-        .withPointerParameter("reg", (void *) &PORTA.OUT)
-        .withUnsignedIntParameter("bit_num", 7);
+        //Selects the ADC pin/channel
+        mock().expectOneCall("RegEdit_OR_Num")
+            .withPointerParameter("reg", (void *) &ADMUX)
+            .withUnsignedIntParameter("num", adc_channel);
 
-    //Set the ISC(input sense config) to disable digital input
-    //buffering and reduce the noise on ADC usage.
-    mock().expectOneCall("RegEdit_SetBit")
-        .withPointerParameter("reg", (void *) &PORTA.PIN7CTRL)
-        .withUnsignedIntParameter("bit_num", PORT_ISC_INPUT_DISABLE_gc);
-
-    */
-    ADC_Init(3);
+        ADC_Init(adc_channel);
+    }
 }
 
 TEST(test_ADC, ADC_InitPortAPin0UsesCorrectRegisters)