From 718a908a9d2d7af8a1ffbb740f66f58dbe191394 Mon Sep 17 00:00:00 2001
From: ole00 <ole00@post.cz>
Date: Sun, 31 Mar 2024 14:55:32 +0100
Subject: [PATCH] sketch: improve pinmuxing when inactive

Previously unused pins were always set as output low.
Now, they are output low when active operation is in
progress, and they are set as input when inactive.
---
 afterburner.ino | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/afterburner.ino b/afterburner.ino
index 627c578..262eed4 100644
--- a/afterburner.ino
+++ b/afterburner.ino
@@ -482,6 +482,12 @@ static void setFlagBit(uint8_t flag, uint8_t value) {
     }
 }
 
+static void setPinMuxUnused(uint8_t pin, uint8_t pm) {
+  // set to OUTPUT during active GAL operation and to INPUT when GAL is inactive
+  pinMode(pin, pm);
+  digitalWrite(pin, LOW);
+}
+
 static void setPinMux(uint8_t pm) {
   // ensure pull-up is enabled during reading and disabled when inactive on DOUT pin
   uint8_t doutMode = pm == OUTPUT ? INPUT_PULLUP: INPUT;
@@ -507,11 +513,9 @@ static void setPinMux(uint8_t pm) {
     // ensure ZIF10 is Grounded via transistor
     digitalWrite(PIN_ZIF_GND_CTRL, pm == OUTPUT ? HIGH: LOW);
 
-    //pull down unused pins
-    pinMode(PIN_ZIF15, pm);
-    pinMode(PIN_ZIF16, pm);
-    digitalWrite(PIN_ZIF15, LOW);
-    digitalWrite(PIN_ZIF16, LOW);
+    //pull down unused pins when active
+    setPinMuxUnused(PIN_ZIF15, pm);
+    setPinMuxUnused(PIN_ZIF16, pm);
     break;
   
   case GAL20V8:
@@ -525,10 +529,10 @@ static void setPinMux(uint8_t pm) {
     // ensure ZIF10 GND pull is disabled
     digitalWrite(PIN_ZIF_GND_CTRL, LOW);
 
-    //pull down unused pins
-    digitalWrite(PIN_ZIF14, LOW);
-    digitalWrite(PIN_ZIF16, LOW);
-    digitalWrite(PIN_ZIF23, LOW);
+    //pull down unused pins when active
+    setPinMuxUnused(PIN_ZIF14, pm);
+    setPinMuxUnused(PIN_ZIF16, pm);
+    setPinMuxUnused(PIN_ZIF23, pm);
 
     break;
 
@@ -549,11 +553,11 @@ static void setPinMux(uint8_t pm) {
     // ensure ZIF10 GND pull is disabled
     digitalWrite(PIN_ZIF_GND_CTRL, LOW);
 
-    //pull down unused pins
-    digitalWrite(PIN_ZIF15, LOW);
-    digitalWrite(PIN_ZIF16, LOW);
-    digitalWrite(PIN_ZIF22, LOW);
-    digitalWrite(PIN_ZIF23, LOW);
+    //pull down unused pins when active
+    setPinMuxUnused(PIN_ZIF15, pm);
+    setPinMuxUnused(PIN_ZIF16, pm);
+    setPinMuxUnused(PIN_ZIF22, pm);
+    setPinMuxUnused(PIN_ZIF23, pm);
     break;
   
   case GAL6001:
@@ -567,11 +571,11 @@ static void setPinMux(uint8_t pm) {
     // ensure ZIF10 GND pull is disabled
     digitalWrite(PIN_ZIF_GND_CTRL, LOW);
 
-    //pull down unused pins
-    digitalWrite(PIN_ZIF3, LOW);
-    digitalWrite(PIN_ZIF15, LOW);
-    digitalWrite(PIN_ZIF16, LOW);
-    digitalWrite(PIN_ZIF22, LOW);
+    //pull down unused pins when active
+    setPinMuxUnused(PIN_ZIF3, pm);
+    setPinMuxUnused(PIN_ZIF15, pm);
+    setPinMuxUnused(PIN_ZIF16, pm);
+    setPinMuxUnused(PIN_ZIF22, pm);
     break;
 
   }