Save MIDI channel to EPROM, add EPROM save indicator

purrChestrion-arduino/gfx.h

@@ -54,3 +54,13 @@ const unsigned char midich [] PROGMEM = {
 	0xe0, 0x7f, 0x98, 0x66, 0x78, 0xf1, 0xe3, 0xc7, 0xff, 0xe1, 0xe0, 0x3f, 0x98, 0x66, 0x00, 0x00, 
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
+
+
+// 'savetorom', 32x12px
+#define SAVETOROM_WIDTH   32
+#define SAVETOROM_HEIGHT    12
+const unsigned char savetorom [] PROGMEM = {
+	0x00, 0x05, 0x55, 0x54, 0x00, 0x0f, 0xff, 0xfe, 0x01, 0x0c, 0x00, 0x02, 0x01, 0x8c, 0x00, 0x02, 
+	0x01, 0xcd, 0x89, 0xb2, 0xbf, 0xed, 0x55, 0x54, 0x5f, 0xed, 0x95, 0x14, 0x01, 0xcd, 0x49, 0x12, 
+	0x01, 0x8c, 0x00, 0x02, 0x01, 0x0c, 0x00, 0x02, 0x00, 0x0f, 0xff, 0xfe, 0x00, 0x05, 0x55, 0x54
+};

purrChestrion-arduino/purrChestrion-arduino.ino

@@ -1,8 +1,10 @@
 #define FW_VER 1.0
 #define USE_OLED true // OLED displays
 #define USE_ENCODER true
+#define EEPROM_MIDI_CHANNEL_ADDR 0 // Address to save MIDI channel in EEPROM
 
 // include libraries
+#include <EEPROM.h>
 #include <Adafruit_MCP23X17.h>
 #include <MIDI.h>
 
@@ -23,22 +25,24 @@
   int lastClk = HIGH;
 #endif
 
+unsigned long lastChannelChangeTime = 0;
+bool channelChanged = false;
+const unsigned long saveDelay = 2000; // 2 seconds
+
+bool showSavedMessage = false;
+unsigned long savedMessageStart = 0;
+const unsigned long savedMessageDuration = 3000; // 1 second
+
 // Instantiate libraries
 Adafruit_MCP23X17 mcp1; // First MCP23017
 Adafruit_MCP23X17 mcp2; // Second MCP23017
 
 // Default hardware MIDI. SoftwareSerial is too slow...
 MIDI_CREATE_DEFAULT_INSTANCE();
-//                        A7 A6 A5 A4 A3 A2 A1 A0  <-- GPIO A
-// MCP pins               28 27 26 25 24 23 22 21 20 19 18 17 16 15    
-// 8 = pin 1             ╔══════════════════════════════════════════╗ 
-// 9 = pin 2             ╠                 MCP23017                 ║
-// 10 = pin 3            ╚══════════════════════════════════════════╝
-//                        01 02 03 04 05 06 07 08  9 10 11 12 13 14
-//                        B0 B1 B2 B3 B4 B5 B6 B7  <-- GPIO B
 
 // Default MIDI channel
 byte currentMidiChannel = MIDI_CHANNEL_OMNI; //8; // Default MIDI channel
+byte savedChannel = EEPROM.read(EEPROM_MIDI_CHANNEL_ADDR);
 
 // Struct for 2 MCP chips. 
 struct MCPOutput {
@@ -95,7 +99,7 @@ MCPOutput noteToMCP[32] = {
 void updateOLED() {
 #if USE_OLED
     oled.clearDisplay();
-    oled.drawBitmap(0, 13, midich, MIDICH_WIDTH, MIDICH_HEIGHT, 1);
+    oled.drawBitmap(0, 12, midich, MIDICH_WIDTH, MIDICH_HEIGHT, 1);
     oled.setCursor(86, 32);
     oled.setTextColor(SSD1306_WHITE);
   if (currentMidiChannel == MIDI_CHANNEL_OMNI) {
@@ -103,6 +107,11 @@ void updateOLED() {
   } else {
     oled.print(currentMidiChannel);
   }
+
+  if (showSavedMessage) {
+    oled.drawBitmap(88, 0, savetorom, SAVETOROM_WIDTH, SAVETOROM_HEIGHT, 1);
+  }
+
   oled.display();
 #endif
 }
@@ -111,23 +120,39 @@ void checkEncoder() {
   #if USE_ENCODER
     int newClk = digitalRead(ENCODER_CLK);
     if (newClk != lastClk && newClk == LOW) {
+      int newChannel = currentMidiChannel;
+
       if (digitalRead(ENCODER_DT) == LOW) {
-        currentMidiChannel++;
+        newChannel++;
       } else {
-        currentMidiChannel--;
+        newChannel--;
       }
 
-      // Wraparound: OMNI = 0, channels 1–16
-      if (currentMidiChannel > 16) currentMidiChannel = 0;
-      if (currentMidiChannel < 0) currentMidiChannel = 16;
+      if (newChannel > 16) newChannel = 0;
+      if (newChannel < 0)  newChannel = 16;
 
-      updateOLED();
+      if (newChannel != currentMidiChannel) {
+        currentMidiChannel = newChannel;
+        updateOLED();
+
+        // Mark that channel changed and restart delay timer
+        lastChannelChangeTime = millis();
+        channelChanged = true;
+      }
     }
     lastClk = newClk;
   #endif
 }
 
+
 void setup() {
+  // Validate saved midi channel in EEPROM
+  if (savedChannel <= 16) {
+    currentMidiChannel = savedChannel;
+  } else {
+    currentMidiChannel = MIDI_CHANNEL_OMNI;
+  }
+
   #if USE_OLED
     if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // I2C addr 0x3C
       // Don't halt if missing, just skip display
@@ -175,6 +200,26 @@ void loop() {
     checkEncoder();
   #endif
   
+  // Save channel if change timeout has passed
+  if (channelChanged && (millis() - lastChannelChangeTime >= saveDelay)) {
+    EEPROM.update(EEPROM_MIDI_CHANNEL_ADDR, currentMidiChannel);
+    channelChanged = false;
+
+    // Show "Saved" message
+    showSavedMessage = true;
+    savedMessageStart = millis();
+    #if USE_OLED
+      updateOLED();
+    #endif
+  }
+
+  if (showSavedMessage && (millis() - savedMessageStart >= savedMessageDuration)) {
+    showSavedMessage = false;
+    #if USE_OLED
+      updateOLED();  // Return to normal channel display
+    #endif
+  }
+
   // LED feedback
   if (ledActive && millis() - ledOnTime >= ledDuration) {
     digitalWrite(LED_BUILTIN, LOW);

purrChestrion-board/purrChestrion-board/~purrChestrion-board.kicad_sch.lck

@@ -0,0 +1 @@
+{"hostname":"Aletheia","username":"sgilissen"}