[ESP32C3] Allow GPIO 11, 12, 13 to be used on specific boards

letscontrolit · Dec 10, 2024 · 150b10f · 150b10f
1 parent 30e4197
commit 150b10f
Show file tree

Hide file tree

Showing 2 changed files with 30 additions and 7 deletions.
diff --git a/docs/source/Reference/GPIO.rst b/docs/source/Reference/GPIO.rst
@@ -366,9 +366,14 @@ ESP32-C3 SPI flash pins
 
 Pins connected to flash or PSRAM should not be used for anything else.
 
+On boards with embedded flash, these pins cannot be used:
+
 * GPIO-11: Flash voltage selector
 * GPIO-12 ... -17: Connected to flash
 
+On boards with external flash, GPIO-11, GPIO-12 and GPIO-13 can be selected.
+However special care should be taken as some boards can still have these pins wired to the flash chip.
+
 .. note:: By default VDD_SPI is the power supply pin for embedded flash or external flash.  It can only be used as GPIO-11 only when the chip is connected to an external flash, and this flash is powered by an external power supply.
 
 

diff --git a/src/src/Helpers/Hardware_GPIO.cpp b/src/src/Helpers/Hardware_GPIO.cpp
@@ -168,17 +168,35 @@ bool getGpioInfo(int gpio, int& pinnr, bool& input, bool& output, bool& warning)
   }
 
   if (gpio == 11) {
-    // By default VDD_SPI is the power supply pin for embedded flash or external flash. It can only be used as GPIO11
-    // only when the chip is connected to an external flash, and this flash is powered by an external power supply
-    input   = false;
-    output  = false;
+    if (getChipFeatures().embeddedFlash) {
+      // See: https://www.letscontrolit.com/forum/viewtopic.php?p=71880#p71874
+      //
+      // By default VDD_SPI is the power supply pin for embedded flash or external flash. 
+      // It can only be used as GPIO11 only when the chip is connected to an 
+      // external flash, and this flash is powered by an external power supply
+      input   = false;
+      output  = false;
+    }
     warning = true;
   }
 
   if (isFlashInterfacePin_ESPEasy(gpio)) {
-    // Connected to the integrated SPI flash.
-    input   = false;
-    output  = false;
+    if (getChipFeatures().embeddedFlash) {
+      // Connected to the integrated SPI flash.
+      input   = false;
+      output  = false;
+    } else {
+      // See: https://www.letscontrolit.com/forum/viewtopic.php?p=71880#p71874
+      if (gpio == 12 || gpio == 13) {
+        // SPIHD/GPIO12
+        // SPIWP/GPIO13
+        if (ESP.getFlashChipMode() != FM_DOUT && 
+            ESP.getFlashChipMode() != FM_DIO) {
+          input   = false;
+          output  = false;
+        }
+      }
+    }
     warning = true;
   }