luckydizzier · luckydizzier · Jun 19, 2025 · Jun 19, 2025
diff --git a/docs/configuration/pins.md b/docs/configuration/pins.md
@@ -1,20 +1,20 @@
 # Pin Assignments
 
-This table lists all recommended connections for the DDS-Controller hardware. The ESP8266-01 module works at **3.3V** logic levels only. All peripherals except the LCD shield must be connected on Arduino pins **20** and above.
+This table lists all recommended connections for the DDS-Controller hardware. The ESP8266-01 module works at **3.3V** logic levels only. All peripherals except the LCD shield are placed on pins **20** and above. Change the values in `firmware/config/pins_config.h` if you use a different layout.
 
 | Arduino Pin | Peripheral  | Function           |
 |-------------|-------------|-------------------|
 | 8,9,4,5,6,7 | LCD Shield  | RS,E,D4,D5,D6,D7  |
 | A0          | LCD Shield  | Buttons ADC       |
-| 10          | AD9850      | WCLK              |
-| 11          | AD9850      | FQUD              |
-| 12          | AD9850      | DATA              |
-| 13          | AD9850      | RESET             |
 | 20          | ESP8266-01  | RX (from Due TX)  |
 | 21          | ESP8266-01  | TX (to Due RX)    |
-| 24          | ESP8266-01  | GPIO2 status LED  |
-| 25          | DDS Output  | Control line      |
-| 26          | ESP8266-01  | GPIO0 (OTA)       |
+| 22          | AD9850      | WCLK              |
+| 23          | AD9850      | FQUD              |
+| 24          | AD9850      | DATA              |
+| 25          | AD9850      | RESET             |
+| 26          | ESP8266-01  | GPIO2 status LED  |
+| 27          | DDS Output  | Control line      |
+| 28          | ESP8266-01  | GPIO0 (OTA)       |
 
 ```
 D20..D53  -> custom peripherals

diff --git a/docs/hardware/esp8266.md b/docs/hardware/esp8266.md
@@ -15,4 +15,4 @@ The ESP8266-01 module is integrated as a WiFi bridge for the DDS-Controller. It
 - **GPIO0_LED** (GPIO0) controls a WiFi status LED whenever OTA updates are enabled. Otherwise this pin remains un-driven so the Arduino Due can repurpose it.
 - UART pins start from Due pin **20** upward to avoid conflicts with the LCD shield.
 
-Use level shifting if any connection might expose the ESP8266-01 to 5V. See the in-code comments in `firmware/esp/main.cpp` for further notes.
+Use level shifting if any connection might expose the ESP8266-01 to 5V. Pin numbers can be remapped in `firmware/config/pins_config.h`. See the in-code comments in `firmware/esp/main.cpp` for further notes.
diff --git a/docs/hardware/pinmap.md b/docs/hardware/pinmap.md
@@ -1,20 +1,20 @@
 # Hardware Pin Mapping – DDS-Controller
 
-> _This document acts as the single source of truth for wiring. See `firmware/shared/config/pins.h` for the authoritative definitions._
+> _This document acts as the single source of truth for wiring. Pin numbers are configured in `firmware/config/pins_config.h` and re-exported via `firmware/shared/config/pins.h`._
 
 | Arduino Due Pin | Peripheral        | Peripheral Pin | Notes                              |
 |-----------------|-------------------|----------------|------------------------------------|
 | 8, 9, 4, 5, 6, 7| LCD Keypad Shield | RS,E,D4,D5,D6,D7 | Uses standard Arduino shield layout |
 | A0              | LCD Keypad Shield | Buttons ADC    | Reads multiple buttons via resistor ladder |
-| 10              | AD9850 DDS        | WCLK           | Serial clock to DDS module         |
-| 11              | AD9850 DDS        | FQUD           | Frequency update                   |
-| 12              | AD9850 DDS        | DATA           | Serial data                        |
-| 13              | AD9850 DDS        | RESET          | Module reset                       |
-| 24              | ESP8266-01        | GPIO2          | WiFi status LED                    |
-| 26              | ESP8266-01        | GPIO0          | OTA LED or Arduino control |
-| 20              | ESP8266-01        | RX             | Connected to Due TX (SoftwareSerial) |
-| 21              | ESP8266-01        | TX             | Connected to Due RX (SoftwareSerial) |
-| 25              | DDS Output Enable | Control line   | Toggles DDS output                 |
+| 20              | ESP8266-01        | RX             | SoftwareSerial RX from Due |
+| 21              | ESP8266-01        | TX             | SoftwareSerial TX to Due |
+| 22              | AD9850 DDS        | WCLK           | Serial clock to DDS module |
+| 23              | AD9850 DDS        | FQUD           | Frequency update |
+| 24              | AD9850 DDS        | DATA           | Serial data |
+| 25              | AD9850 DDS        | RESET          | Module reset |
+| 26              | ESP8266-01        | GPIO2          | WiFi status LED |
+| 27              | DDS Output Enable | Control line   | Toggles DDS output |
+| 28              | ESP8266-01        | GPIO0          | OTA trigger (keep high unless flashing) |
 
 **Safety Notice:** The ESP8266-01 module operates at **3.3V** logic levels only. Connecting it directly to 5V will permanently damage the module.
 

diff --git a/firmware/config/pins_config.h b/firmware/config/pins_config.h
@@ -0,0 +1,27 @@
+#ifndef FIRMWARE_PINS_CONFIG_H
+#define FIRMWARE_PINS_CONFIG_H
+
+// Default pin mapping for DDS-Controller.
+// Modify these values to match your wiring.
+// All custom peripherals start from pin 20 and above.
+
+// ESP8266-01 SoftwareSerial
+#define PIN_ESP_RX 20
+#define PIN_ESP_TX 21
+
+// DDS module (AD9850)
+#define PIN_DDS_WCLK 22
+#define PIN_DDS_FQUD 23
+#define PIN_DDS_DATA 24
+#define PIN_DDS_RESET 25
+
+// Status LED on ESP GPIO2
+#define PIN_ESP_LED 26
+
+// Output enable control for DDS
+#define PIN_OUTPUT_CONTROL 27
+
+// ESP8266 GPIO0 (reserved for OTA)
+#define PIN_ESP_GPIO0 28
+
+#endif // FIRMWARE_PINS_CONFIG_H
diff --git a/firmware/due/main.ino b/firmware/due/main.ino
@@ -33,6 +33,7 @@ void setup() {
   esp_begin(espSerial, parser);
   pinMode(PIN_ESP_LED, OUTPUT);
 #if !USE_ESP_OTA
+  // Keep ESP8266 in normal boot mode when OTA is disabled
   pinMode(PIN_ESP_GPIO0, OUTPUT);
   digitalWrite(PIN_ESP_GPIO0, HIGH);
 #endif
@@ -49,6 +50,17 @@ void setup() {
 
 void loop() {
   menu.update();
+#ifdef USE_ESP
+  static unsigned long lastLedToggle = 0;
+  if (millis() - lastLedToggle > 1000) {
+    digitalWrite(PIN_ESP_LED, !digitalRead(PIN_ESP_LED));
+    lastLedToggle = millis();
+  }
+#if !USE_ESP_OTA
+  // Ensure the ESP remains in run mode when OTA is disabled
+  digitalWrite(PIN_ESP_GPIO0, HIGH);
+#endif
+#endif
 
   if (Serial.available()) {
     String cmd = Serial.readStringUntil('\n');

diff --git a/firmware/shared/config/config.h b/firmware/shared/config/config.h
@@ -15,7 +15,4 @@
 
 #define ESP_BAUD_RATE 9600
 
-// Optional pin for controlling ESP8266 GPIO0 when OTA is disabled
-#define PIN_ESP_GPIO0 26
-
 #endif // CONFIG_H
diff --git a/firmware/shared/config/pins.h b/firmware/shared/config/pins.h
@@ -2,21 +2,60 @@
 #define CONFIG_PINS_H
 
 // Centralized pin definitions for DDS-Controller hardware
-// Adjust these values to match the wiring as documented in docs/hardware/pinmap.md
+// All numeric values are provided by firmware/config/pins_config.h
 
-// DDS (AD9850)
-#define PIN_DDS_WCLK   10
-#define PIN_DDS_FQUD   11
-#define PIN_DDS_DATA   12
-#define PIN_DDS_RESET  13
+#include "../../config/pins_config.h"
 
-// ESP8266-01 communication via SoftwareSerial
-#define PIN_ESP_RX     20  // Due TX to ESP8266 RX
-#define PIN_ESP_TX     21  // Due RX to ESP8266 TX
-#define PIN_ESP_LED    24  // GPIO2 on ESP8266
-
-// Control output
-#define PIN_OUTPUT_CONTROL 25
+// Re-export for firmware modules
 #define OUTPUT_CONTROL_PIN PIN_OUTPUT_CONTROL
 
+// Validate that no two pins share the same number
+#define VALIDATE_PIN_UNIQUE(a,b) static_assert((a) != (b), "Pin conflict: " #a " and " #b)
+
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_ESP_TX);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_DDS_WCLK);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_DDS_FQUD);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_DDS_DATA);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_DDS_RESET);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_ESP_RX, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_DDS_WCLK);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_DDS_FQUD);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_DDS_DATA);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_DDS_RESET);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_ESP_TX, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_DDS_FQUD);
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_DDS_DATA);
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_DDS_RESET);
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_DDS_WCLK, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_DDS_FQUD, PIN_DDS_DATA);
+VALIDATE_PIN_UNIQUE(PIN_DDS_FQUD, PIN_DDS_RESET);
+VALIDATE_PIN_UNIQUE(PIN_DDS_FQUD, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_DDS_FQUD, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_DDS_FQUD, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_DDS_DATA, PIN_DDS_RESET);
+VALIDATE_PIN_UNIQUE(PIN_DDS_DATA, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_DDS_DATA, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_DDS_DATA, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_DDS_RESET, PIN_ESP_LED);
+VALIDATE_PIN_UNIQUE(PIN_DDS_RESET, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_DDS_RESET, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_ESP_LED, PIN_OUTPUT_CONTROL);
+VALIDATE_PIN_UNIQUE(PIN_ESP_LED, PIN_ESP_GPIO0);
+
+VALIDATE_PIN_UNIQUE(PIN_OUTPUT_CONTROL, PIN_ESP_GPIO0);
+
+#undef VALIDATE_PIN_UNIQUE
+
 #endif // CONFIG_PINS_H