From 0ccad0460736ce1c1bc6611366857f1ffc17127f Mon Sep 17 00:00:00 2001
From: wke67 <wke67@t-online.de>
Date: Wed, 8 Jul 2026 16:03:35 +0200
Subject: [PATCH] fixed analogReference(), it did not reflect the last changes
 to INTERNAL.. defines. Checking of mode bits is already done by
 check_valid_analog_ref(), no need to check twice.

---
 megaavr/cores/dxcore/wiring_analog.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/megaavr/cores/dxcore/wiring_analog.c b/megaavr/cores/dxcore/wiring_analog.c
index ef69aee1..2fc1d6d0 100644
--- a/megaavr/cores/dxcore/wiring_analog.c
+++ b/megaavr/cores/dxcore/wiring_analog.c
@@ -20,6 +20,7 @@
 */
 
 
+#include "avr/io.h"
 #include "wiring_private.h"
 #include "pins_arduino.h"
 #include "Arduino.h"
@@ -390,12 +391,8 @@ inline __attribute__((always_inline)) void check_valid_resolution(uint8_t res) {
 
   /* Ex Version*/
   void analogReference(uint8_t mode) {
-    check_valid_analog_ref(mode);
-    if (mode > 7)
-      mode &= 7;
-    if (mode != 1 && mode != 3) {
-      ADC0.CTRLC = mode;
-    }
+    check_valid_analog_ref(mode); // does all the checking
+    ADC0.CTRLC = (ADC0.CTRLC & ~(ADC_REFSEL_gm)) | (mode & (ADC_REFSEL_gm));
   }
 /* Ex Version*/
   inline uint8_t getAnalogReference() {
@@ -699,16 +696,8 @@ inline __attribute__((always_inline)) void check_valid_resolution(uint8_t res) {
     return _analog_options & 0x0F;
   }
   void analogReference(uint8_t mode) {
-    check_valid_analog_ref(mode);
-    #if defined(STRICT_ERROR_CHECKING)
-      if (mode > 7) return;
-    #else
-      mode &= 7;
-    #endif
-    if (mode != 1 && mode != 3) {
-      ADC0.CTRLC = mode;
-    }
-    // Uh? Is that it? That was, ah, a tiny bit simpler.
+    check_valid_analog_ref(mode);  // does all the checking
+    ADC0.CTRLC = (ADC0.CTRLC & ~(ADC_REFSEL_gm)) | (mode & (ADC_REFSEL_gm));
   }
   inline uint8_t getAnalogReference() {
     uint8_t r = ADC0.CTRLC & ADC_REFSEL_gm;
@@ -950,10 +939,8 @@ inline __attribute__((always_inline)) void check_valid_resolution(uint8_t res) {
    ########  ##     ## ##       ########  ########  ##       ########  ########           */
 
   void analogReference(uint8_t mode) {
-    check_valid_analog_ref(mode);
-    if (mode < 7 && mode != 4) {
-      VREF.ADC0REF = (VREF.ADC0REF & ~(VREF_REFSEL_gm))|(mode);
-    }
+    check_valid_analog_ref(mode); // does all the checking
+    VREF.ADC0REF = (VREF.ADC0REF & ~(VREF_REFSEL_gm))|(mode & (VREF_REFSEL_gm));
   }
 
   int16_t analogRead(uint8_t pin) {